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Product Sample For questions or more information, contact: Cambium Learning Voyager 17855 Dallas Parkway, Ste. 400 │ Dallas, TX 75287 1‐888‐399‐1995 www.voyagerlearning.com CHAPTER 9 Objective 2 Use the greatest common factor and the Distributive Property to factor polynomials with the grouping technique, and use these techniques to solve equations. Objective 2 Pretest Students complete the Objective 2 Pretest on the same day as the Objective 1 Posttest. Using the Results • Score the pretest and update the class record card. • If the majority of students do not demonstrate mastery of the concepts, use the 5-Day Instructional Plan for Objective 2. Chapter 9 • Objective 2 Pretest • If the majority of students demonstrate mastery of the concepts, use the 3-Day Instructional Plan for Objective 2. Name __________________________________________ Date ____________________________ Factor the polynomials using the greatest common factor (GCF) and the distributive property. x 2 + 3x 2. 9x 4y 3 + 12x 2y 5 – 15x 3y 3. 4c 2d – 8c 3d 2 4. 2m 2 – 10m 5. 18s 4t 3 + 9s 2t 4 – 27s 3t 5 –2x 2 – 4x = 0 7. 5a 2 + 30a = 0 6b 2 – 12b = 0 9. 0 = 9x 2 – 3x 1. x(x + 3) 4c 2d(1 – 2cd) 3x 2y(3x 2y 2 + 4y 4 – 5x) 2m(m – 5) 9s2t 3(2s 2 + t – 3st 2) Solve the equations. 6. 8. 126 786 6b(b – 2) = 0 b = 0, 2 5a(a + 6) = 0 a = 0, –6 3x(3x – 1) = 0 x = 0, 1 3 –3a 2 – 9a = 0 –3a(a + 3) = 0 a = 0, –3 Chapter 9 • Objective 2 Chapter 9 • Objective 2 Inside Algebra Copyright 2011 Cambium Learning Sopris West.® All rights reserved. 10. –2x(x + 2) = 0 x = 0, –2 Objective 2 Goals and Activities Objective 2 Goals The following activities, when used with the instructional plans on pages 788 and 789, enable students to: • Factor the polynomial 24x 2 – 16x using the greatest common factor (GCF) and the Distributive Property to get 8x(3x − 2) • Factor the polynomial 18x 2y 3 + 15x 3y 5 – 21x 4y 2 using the greatest common factor (GCF) and the Distributive Property to get 3x 2y 2(6y + 5xy 3 − 7x 2) • Solve the equation 2x 2 – 4x = 0 to get x = 0, 2 • Solve the equation 3x 2 + 6x = 0 to get x = 0, −2 Objective 2 Activities Concept Development Activities ★CD 1 Using CD 2 Finding What’s in Common— Part 1, page 792 Algebra Tiles, page 790 CD 3 Finding What’s in Common— Part 2, page 793 CD 4 Factoring and Solving, page 795 Practice Activities PA 1 Drawing Cards, page 796 PA 2 Solving Equations, page 797 PA 3 Finding the Solutions, page 798 Progress-Monitoring Activities PM 1 Apply Skills 1, page 799 PM 2 Apply Skills 2, page 800 PM 3 Apply Skills 3, page 801 Problem-Solving Activity ★ ★PS 1 Using the Length and Width of a Rectangle, page 802 Ongoing Assessment Posttest Objective 2, page 803 Pretest Objective 3, page 804 CD = Concept Development PM = Progress Monitoring PS = Problem Solving PA = Practice Activity ★ = Includes Problem Solving Chapter 9 • Objective 2 787 CHAPTER 9 Objective 2 Instructional Plans 5-Day Instructional Plan Use the 5-Day Instructional Plan when pretest results indicate that students would benefit from a slower pace. This plan is used when the majority of students need more time or did not demonstrate mastery on the pretest. ★CD 1 Using Algebra Tiles Day 1 CD 2 Finding What’s in Common—Part 1 PM 1 Apply Skills 1 ACCELERATE Day 2 DIFFERENTIATE PA 1 Drawing Cards CD 3 Finding What’s in Common— Part 2 PM 2 Apply Skills 2 PA 1 Drawing Cards CD 4 Factoring and Solving PM 2 Apply Skills 2 PA 2 Solving Equations CD 4 Factoring and Solving PM 3 Apply Skills 3 PA 3 Finding the Solutions Day 3 Day 4 ★PS 1 Using the Length and Width of a Rectangle PM 3 Apply Skills 3 Day 5 Posttest Objective 2 Pretest Objective 3 788 CD = Concept Development PM = Progress Monitoring PS = Problem Solving PA = Practice Activity ★ = Includes Problem Solving Chapter 9 • Objective 2 3-Day Instructional Plan Use the 3-Day Instructional Plan when pretest results indicate that students can move through the activities at a faster pace. This plan is ideal when the majority of students demonstrate mastery on the pretest. This plan does not include all activities. ★CD 1 Using Algebra Tiles CD 3 Finding What’s in Common—Part 2 Day 1 Day 2 ACCELERATE DIFFERENTIATE PM 2 Apply Skills 2 PM 1 Apply Skills 1 CD 4 Factoring and Solving PA 1 Drawing Cards PA 3 Finding the Solutions PM 2 Apply Skills 2 PM 3 Apply Skills 3 CD 4 Factoring and Solving ★PS 1 Using the Length and Width of a Rectangle PA 3 Finding the Solutions PM 3 Apply Skills 3 Day 3 Posttest Objective 2 Pretest Objective 3 CD = Concept Development PM = Progress Monitoring PS = Problem Solving PA = Practice Activity ★ = Includes Problem Solving Chapter 9 • Objective 2 789 Objective 2 Concept Development Activities ★ CD 1 Using Algebra Tiles Use with 5-Day or 3-Day Instructional Plan. In this activity, students factor binomials using algebra tiles. MATERIALS 5.Write 2x 2 + 6x on the board. Tell students to think about how we factor the expression using algebra tiles. Ask students to discuss how we find the dimensions for the length and width. Students should recognize that both a 2 and an x can be factored out. 2x 2 + 6x = 2x (x + 3) • Algebra tiles x2 •Variation: Gizmos Modeling the Factorization of x 2 + bx + c DIRECTIONS 1. Review the following term with students: factor A monomial that evenly divides a value 2.Distribute algebra tiles to students. Have each student build a rectangle with dimensions A • B. B 3.Write x + 3x on the board, and demonstrate how to build a rectangle for that equation. Point out that the area of the rectangle and the factored form of the equation is x(x + 3). x2 x x x x x +3 x2 x x x 4.Have students use algebra tiles to factor several expressions. Sample problems: x 2 + 4x x (x + 4) x 2 − 3x x(x − 3) x 2 + 6x x(x + 6) x 2 + x x(x + 1) ★ = Includes Problem Solving 790 Chapter 9 • Objective 2 x x x +3 x2 x x x x2 x x x x x 2x A 2 x x2 6.Have students build rectangles and name the factors for several more expressions. Sample problems: x 2 + 4x x(x + 4) 2x 2 + 4x 2x (x + 2) x 2 − 5x x(x − 5) 3x 2 + 6x 3x (x + 2) 2x 2 − 6x 2x(x − 3) 7.Discuss the problems and the factors using the Distributive Property. x Variation: Gizmos For this activity, use the tiles in the Gizmo Modeling the Factorization of x 2 + bx + c to model the factoring of these quadratic expressions. • Gizmos Modeling the Factorization of x 2 + bx + c NEXT STEPS • Differentiate 5-Day Instructional Plan: CD 2, page 792—All students, for additional concept development 3-Day Instructional Plan: CD 3, page 793—All students, for additional concept development Chapter 9 • Objective 2 791 Objective 2 Concept Development Activities CD 2 Finding What’s in Common—Part 1 Use with 5-Day Instructional Plan. In this activity, students develop an understanding of GCF. MATERIALS • Blank cards, 48 per group DIRECTIONS 1. Review the following terms with students: 6.If students have difficulty writing the expression from the cards they were dealt, go over an example. factor A monomial that evenly divides a value g reatest common factor (GCF) The largest factor that a set of monomials has in common 2.Divide the class into groups of four. Give one set of 48 cards to each group. Have each group label the cards as follows: •Twelve cards with the number 2 •Twelve cards with the number 3 •Twelve cards with the word red •Twelve cards with the word blue 3.Explain the process for this activity. • O ne student from each group shuffles and deals five cards to each person in the group. The remaining cards are put aside. • E ach student places his or her five cards faceup on the table so all students can look at everyone’s hand. • S tudents look for cards that all four group members have in common. These cards are placed in a new stack in the middle of the table. • T he group members continue this process until their hands no longer have any cards that are common to those of all other members in their group. 4.Tell students the cards that were placed in the center of the table represent the greatest common factor for their group. Have one student from each group share the greatest common factor his or her group found. Have each group write its GCF next to an open parenthesis symbol on a sheet of paper; for example, 2rb(. 5.Explain to students that the cards remaining in their hands represent the portion of their hands that were not common. Have groups list the cards remaining in each group members’ hands, one at a time. Explain to students that these should be listed to the right of the parenthesis with a plus sign between the entry. Have students place a closing parenthesis symbol on the right side of the sum of their leftover cards. 792 Chapter 9 • Objective 2 Examples: Student 1 red, 2, red, blue, 3 or r + 2 + r + b + 3 Student 2 blue, 2, 2, 3, red or b + 2 + 2 + 3 + r Student 3 red, red, 3, blue, 2 or r + r + 3 + b + 2 Student 4 3, blue, 2, red, 3 or 3 + b + 2 + r + 3 Common cards/GCF: red, blue, 2, and 3 or (2)(3)br Leftover cards: Student 1 red or r Student 2 2 Student 3 red or r Student 4 3 Expression: (2)(3)br (r + 2 + r + 3) or (2)(3)br (2 + 3 + 2r) 7.Have students shuffle all the cards and repeat the activity as time allows. 8.At the end of the activity, ask students to write the factored sentences for 3x 2y 2 + 15xy 3 and 12a 2bc 3 + 30a 2bc. 3x 2y 2 + 15xy 3 = 3xy 2 (x + 5y); 12a 2bc 3 + 30a 2bc = 6a 2bc(2c 2 + 5) NEXT STEPS • Differentiate 5-Day Instructional Plan: PM 1, page 799—All students, to assess progress Objective 2 Concept Development Activities CD 3 Finding What’s in Common—Part 2 Use with 5-Day or 3-Day Instructional Plan. In this activity, students develop an understanding of GCF. MATERIALS •Blank cards, 52 per group, or the card sets from CD 2 and 4 blank cards DIRECTIONS 1. Review the following term with students: factor A monomial that evenly divides a value 2.Divide the class into groups of four. Give each group four blank cards and one set of the 48 cards students made in Concept Development Activity, Finding What’s in Common—Part 1. If students did not complete this activity, give each group 52 blank cards and have them label 48 of the blank cards as follows: •Twelve cards with the number 2 •Twelve cards with the number 3 •Twelve cards with the word red •Twelve cards with the word blue Have the groups keep the four blank cards out of the deck for use later in the activity. 3. Explain the process for this activity. •One student in each group shuffles and deals five cards to each person. The dealer puts the remaining cards aside. •All four group members place the card with their abbreviated hand faceup in the center of the table so all group members may view them. •Students look at the abbreviated hands to find any 2s that are common to all four cards. Students that find 2s write a 2 on a blank piece of paper, then determine the lowest exponent of 2 that appears in the four hands. It is written as an exponent for the 2 they have on their paper. •Students repeat the process for the number 3, for the letter r, and for the letter b. Note: This process will take a while, and it is important you keep students organized so they stay on track. 4.Tell students that once they complete the process, the term they have written on their paper should be the GCF for their group. 5.Have students complete the expression. Tell all students to write an open parenthesis symbol to the right of the GCF on their paper. Have each student determine what would be left if the GCF were removed from his or her hand. Students write these remaining elements inside the open parenthesis. Make sure students remember to put a plus symbol between each student’s leftover cards. The last person should place a closing parenthesis on the right side of his or her term. Example: •Each student places his or her five cards faceup on the table so all students can look at everyone’s hand. Student 1 2, 2, 3, r, r or 22 • 3 • r 2 Student 2 2, 3, 2, r, b or 22 • 3 • b • r Student 3 b , 2, b, r, 3 or 2 • 3 • b 2 • r Student 4 2, 3, 3, r, b or 2 • 32 • b • r •Each student determines the most abbreviated way to write his or her combination of cards. Expression: 2 • 3 • r (2r + 2b + b 2 + 3b) •Each student writes his or her abbreviated hand on one of the four blank cards. They should write the numbers first, followed by the variables, using exponents for any cards that repeat within the hand. Students should write a multiplication symbol between each element of their hands to avoid confusion later (e.g., r, r, 2, 3, 2 should be written as 2 2 • 3 • r 2). GCF: 2 • 3 • r or (2)(3)r Chapter 9 • Objective 2 793 Objective 2 Concept Development Activities 6.After some practice with the cards, have students write a factored sentence for the following: (22 • r • b 2) + (3 • 2 • r 2 • b) + (3 • 2 • r • b 2) + (22 • r • b 2) 2rb(2b + 3r + 3b + 2b) or 2rb(7b + 3r) 7.Have students write factored sentences for some expressions. Sample problems: 8a 2b + 4ab 2 4ab(2a + b) 14a 3b 2c 2 + 7a 2bc 4 7a 2bc 2 (2ab + c 2) NEXT STEPS • Differentiate 5-Day Instructional Plan: PA 1, page 796—All students, for additional practice 3-Day Instructional Plan: PM 2, page 800—Students who demonstrate understanding of the concept, to assess progress PM 1, page 799—Students who need additional support, to assess progress 794 Chapter 9 • Objective 2 Objective 2 Concept Development Activities CD 4 Factoring and Solving Use with 5-Day or 3-Day Instructional Plan. In this activity, students understand the Zero Product Property and use it to solve equations. DIRECTIONS 1.Write a • b = 0 on the board. Ask students what numbers make it a true statement. If students have difficulty, give them a value for a or b, and have them determine the value of the other variable. Examples: factor A monomial that evenly divides a value 6.Write x 2 + 3x = 0 on the board. Elicit from students that the factored form of the equation is x(x + 3) = 0. Explain that by factoring the original problem, you have created an equivalent equation that involves the multiplication of two terms, which can easily be solved using the Zero Product Property. Explain that if x • (x + 3) = 0, then either x = 0 or (x + 3) = 0. Point out that solving these two equation factors yields two answers, x = 0 or x = –3. 7.Solve 4x 2 + 6x = 0 with the class. 2x(2x + 3) = 0; x = 0 or x = – 3 2 If a = 4, what must b equal? 0 8.Have students solve several equations independently. If b = 6, what must a equal? 0 1 , what must b equal? 0 If a = 16 2.Make sure students recognize that no matter what value we pick for a or b, in order for a • b = 0 to be true, one or both of the values must be equal to zero. Refer to this concept as the Zero Product Property. 3.Write 2x • y = 0 on the board. Continue discussing the concept that either x or y must be equal to zero for this equation to be a true statement. Write 2x = 0 and y = 0 on the board, and explain that one or both of these equations must be true if 2x • y = 0. 4.Write a + b = 0 on the board. Have students discuss what combinations work for the equation. Make sure students recognize that many combinations work. 5.Review the following term with students: Examples: Sample problems: x 2 − 9x = 0 x = 0, 9 5x + x 2 = 0 x = 0, –5 2x 2 − 6x = 0 x = 0, 3 2x + 2 = 0 x = –1 NEXT STEPS • Differentiate 5-Day Instructional Plan: PA 2, page 797—Students who are on the accelerated path, for additional practice PA 3, page 798—Students who are on the differentiated path, for additional practice 3-Day Instructional Plan: PA 3, page 798—All students, for additional practice (1, −1) 1 + (−1) = 0 (2, −2) 2 + (−2) = 0 (8, −8) 8 + (−8) = 0 Emphasize the fact that the Zero Product Property works only for multiplication and that it does not hold for addition. Chapter 9 • Objective 2 795 Objective 2 Practice Activities PA 1 Drawing Cards Use with 5-Day or 3-Day Instructional Plan. In this activity, students find the GCF of polynomials. MATERIALS • Blank cards, one per student Directions 1. Review the following term with students: factor A monomial that evenly divides a value 2.Label one side of each card with an integer starting from 1 and continuing to the number that represents the student population in your class. On the other side of each card, write a monomial that contains a random combination of factorable integers between 1 and 60 and the variables x, y, and/or z. Any variable used may contain an exponent from 1 to 6—for example, 8x 2y 3z 2 . Include cards such as x 2 and 6x. 3.Have students number off from 1 to whatever your class population is. 4.Shuffle the cards and randomly select two of them. Have the two students whose numbers correspond to the numbers on the cards go up to the board. Give them their corresponding cards. 5.Tell the two students to write the monomials from their cards on the board side-by-side with an addition or subtraction symbol between them— for example, 8x 2y 3z 2 + 12xy 2z 2 . 6.Have the rest of the class factor the two monomials and write the GCF on their own papers—for the example, 4xy 2z 2 . Have students work individually. 7.Repeat this process until all cards have been used. If students are confident with this task, make it a competition to see who can get the most correct. 796 Chapter 9 • Objective 2 8.Point out to students that they should have answers for all but their own problem. Alternatively, give them time to get back to their seats to complete that problem as well. NEXT STEPS • Differentiate 5-Day and 3-Day Instructional Plans: PM 2, page 800—All students, to assess progress Objective 2 Practice Activities PA 2 Solving Equations Use with 5-Day Instructional Plan. In this activity, students solve equations. Directions 3.Put students in groups of four. Have each student work independently to solve all the equations for his or her group on a new sheet of paper. Instruct the students in each group to compare their answers. If any of the solutions differ, have the group work together to determine the correct answer. 1.Write x 2 ± bx = 0 on the board. Tell students to get out a sheet of paper and write an equation like the one on the board, but substitute a number for b and choose either + or – for the equation. 4.Have each group exchange their eight problems with a different group and solve the new problems. Continue the sharing of problems as time allows. NEXT STEPS • Differentiate Sample answers: x 2 + 10x = 0 x2 − x = 0 5-Day Instructional Plan: PM 3, page 801—All students, to assess progress x 2 + 5x = 0 1 2.Write ax 2 ± bx = 0 on the board. Have students write an equation like the one on the board, but substitute numbers for a and b and choose either + or – for the equation. Sample answers: 3x 2 + 2x = 0 4x 2 + 3 x = 0 2 0.5x 2 − x = 0 The students should now have two equations on their paper. Chapter 9 • Objective 2 797 Objective 2 Practice Activities PA 3 Finding the Solutions Use with 5-Day or 3-Day Instructional Plan. In this activity, students solve equations. MATERIALS Directions 1.Have students form groups of four, and give each group 20 blank cards. Write the following equations on the board, and tell the groups to put one equation per card on six of the blank cards: x 2 + 4x = 0 3x + x 2 = 0 2x 2 − 4x = 0 x 2 + 2x = 0 x 2 − 3x = 0 2.Tell students to write the following solutions, one solution per card, on the remaining 14 cards: 0, 0, 0, 0, 0, 0, 1, −1, 2, −2, 3, −3, 4, −4 3.Explain the game rules to students. •Each group shuffles their equation cards and their solution cards separately and deals one equation card to each student in the group. The two extra equation cards are set to the side, and the solution cards are placed in a stack facedown. •Each student solves the equation he or she was dealt on a sheet of paper. •After all students in a group are finished solving their equations, the dealer takes the top card from the stack of solution cards and places it next to the stack, facing up. The student keeps the card if it is a solution to his or her equation. 798 Chapter 9 • Objective 2 •Play continues clockwise. •After all solution cards have been selected, each student must show the group that his or her solution cards are correct by solving the original equation to prove it is a true statement. • Blank cards, 20 per group 5x − 5x 2 = 0 •The next player takes the card facing up or the card on the top of the stack of cards that are facedown. He or she keeps the card if it is a solution to his or her equation. 4.Have students separate the cards into equation cards and solution cards, shuffle all the equation cards, and deal the cards again. NEXT STEPS • Differentiate 5-Day and 3-Day Instructional Plans: PM 3, page 801—All students, to assess progress Progress-Monitoring Activities PM 1 Apply Skills 1 Use with 5-Day or 3-Day Instructional Plan. MATERIALS • Interactive Text, page 342 DIRECTIONS 1.Have students turn to Interactive Text, page 342, Apply Skills 1. 3.Monitor student work, and provide feedback as necessary. Watch for: •Do students recognize when they have not found all the factors that can be pulled out? Name __________________________________________ Date __________________________ A p p ly S k i l l S 1 Factor the polynomials using the greatest common factor (GCF) and the Distributive Property. Example: 2x 2 + 6x = 2x(x + 3) 1. x 2 + 6x = 2. x 2 – 4x = 3. x 2 + 5x = 4. 7x – x 2 = 5. x 2 + x = 6. x 2 – 11x = 7. 3x 2 + x = 8. 2x 2 – 4x = x(x + 6) x(x + 5) x(x + 1) x(3x + 1) x(x – 4) x(7 – x) x(x – 11) 2x(x – 2) 6x 2 + 8x = 10. 3x 2 + 9x = 11. m 2n 2 + mn 3 = 12. m 3n 2 + m 2n 3 = 13. 2m 2n 2 + 8mn 2 = 14. 5m 4n – 40m 5n 3 = 15. –8m 2n 5 + 32m 2n 3 = 16. 20a 3b 5 + 50a 5b 3 = 9. 2x(3x + 4) mn 2(m + n) 2mn 2(m + 4) –8m 2n 3(n 2 – 4) 17. 12a 2b + 18a 3b 3 = 6a 2b(2 + 3ab 2) 19. 342 2a 5b 3 + 22a 5b 2 = 2a 5b 2(b + 11) Chapter 9 • Objective 2 • PM 1 3x(x + 3) m 2n 2(m + n) 5m4n(1 – 8mn 2) 10a 3b 3(2b 2 + 5a 2) 18. –8a 4b – 48a 2b 2 = –8a 2b(a 2 + 6b) 20. 14a 3b – 35a 2b 3 = 7a 2b(2a – 5b 2) Inside Algebra Copyright 2011 Cambium Learning Sopris West.® All rights reserved. 2.Remind students of the key term: greatest common factor (GCF). progress moNitoriNg Objective 2 •Do students compare each factor separately? NEXT STEPS • Differentiate 5-Day Instructional Plan: PA 1, page 796—Students who demonstrate understanding of the concept, for additional practice CD 3, page 793—Students who need additional concept development 3-Day Instructional Plan: PA 1, page 796—All students, for additional practice Chapter 9 • Objective 2 799 Progress-Monitoring Activities PM 2 A p p ly S k i l l S 2 Factor the polynomials using the greatest common factor (GCF) and the Distributive Property. Example: 6x 2 + 36x = 6x(x + 6) Apply Skills 2 1. –2x 2 + 6x = 2. 5x 2 – 15x = 3. –3x 2 + 12x = 4. 5x 2 + 25x = 5. 5m 2n 3 – 35m 5n = 6. 11mn 2 – 33m 4n = 7. –5m 4n – 20m 5n 3 = 8. –8m 2n + 24m 2n2 = Use with 5-Day or 3-Day Instructional Plan. • Interactive Text, page 343 •Do students find the GCF using number trees, algebra tiles, or another method? NEXT STEPS • Differentiate 5-Day and 3-Day Instructional Plans: CD 4, page 795—All students, for additional concept development 800 Chapter 9 • Objective 2 Copyright 2011 Cambium Learning Sopris West.® All rights reserved. 1.Have students turn to Interactive Text, page 343, Apply Skills 2. Watch for: •Do students correctly factor out negatives? –3x(x – 4) –5m 4n(1 + 4mn 2) 5x(x – 3) 5x(x + 5) 11mn(n – 3m 3) –8m 2n(1 – 3n) 9. 24a 3b 5 + 48ab 3 = 10. 16ab 4 + 32ab 2 = 11. –9a 4b – 45a 3b 4 = 12. 13a 3b 2 – 26ab = 13. 7x 4y 3 + 14x 2y 5 – 28x 3y 2 = 14. 6x 4y 2 – 24x 3y + 12xy 5 = 15. –15x 2y – 5xy 4 – 30xy 4 = 16. 10x 4y 3 + 16x 2 – 24y 2 = DIRECTIONS 3.Monitor student work, and provide feedback as necessary. –2x(x – 3) 5m 2n(n 2 – 7m 3) MATERIALS 2.Remind students of the key term: greatest common factor (GCF). progress moNitoriNg Name __________________________________________ Date __________________________ Objective 2 24ab 3(a 2b 2 + 2) –9a 3b(a + 5b 3) 7x 2y 2(x 2y + 2y 3 – 4x) –5xy(3x + 7y 3) 17. –72x 4y + 16x 3y 3 – 20x 2y 2 = –4x 2y(18x 2 – 4xy 2 + 5y) 19. 14ab 2 + 35a 3b 2 – 7a 3b + 70ab 4 = 7ab(2b + 5a 2b – a 2 + 10b 3) Inside Algebra 16ab 2(b 2 + 2) 13ab(a 2b – 2) 6xy(x 3y – 4x 2 + 2y 4) 2(5x 4y 3 + 8x 2 – 12y 2) 18. 12a 5b 3 – 3a 4b 3 + 27a 3b 4 + 9a 3b 4 = 3a 3b 3(4a 2 – a + 12b) 20. –32a 4b 3 + 16a 3b 3 – 4a 3b + 24a 2b 2 = –4a 2b(8a 2b 2 – 4ab 2 + a – 6b) Chapter 9 • Objective 2 • PM 2 343 progress moNitoriNg Objective 2 Progress-Monitoring Activities PM 3 Apply Skills 3 Use with 5-Day or 3-Day Instructional Plan. MATERIALS • Interactive Text, pages 344–345 DIRECTIONS 1.Have students turn to Interactive Text, pages 344–345, Apply Skills 3. A p p ly S k i l l S 3 Factor the polynomials using the greatest common factor (GCF) and the Distributive Property. Example: 3x 2 + 6x = 2x(x – 7) 3. –3x 2 + 12x = 5x(x + 11) 5. 36x + 9x 2 = 2x(x + 5) 2. 2x 2 – 14x = 4. 55x + 5x 2 = 5x(11 + x) 9x(4 + x) Example: 3x 3 3x 2 – 6x = 0 3x(x – 2) = 0 either 3x = 0 or x – 2 = 0 9x(x + 4) = 03 or x – 2 = 0 +2 +2 6. x 2 + 5x = 0 7. x 2 – 3x = 0 8. 4x 2 + 8x = 0 9. 3x 2 – 12x = 0 x(x + 5) = 0 x = 0 or x + 5 = 0 x = –5 x = 0, –5 344 x(x – 3) = 0 x = 0 or x – 3 = 0 x=3 x = 0, 3 Chapter 9 • 3x(x – 4) = 0 3x = 0 or x – 4 = 0 x = 0 or x = 4 x = 0, 4 Objective 2 • PM 3 Inside Algebra Name __________________________________________ Date __________________________ A p p ly S k i l l S 3 10. 9x 2 + 27x = 0 11. x 2 + 8x = 0 12. 2x 2 + x = 0 13. 10x 2 – 5x = 0 9x(x + 3) = 0 9x = 0 or x + 3 = 0 x = 0 or x = –3 x = 0, –3 NEXT STEPS • Differentiate 5-Day and 3-Day Instructional Plans: PS 1, page 802—Students who are on the accelerated path, to develop problem-solving skills x(2x + 1) = 0 x = 0 or 2x + 1 = 0 2x = –1 Objective 2 Posttest, page 803—Students who are on the differentiated path x = –1 2 x = 0, –1 2 14. 12x 2 + 4x = 0 4x(3x + 1) = 0 4x = 0 or 3x + 1 = 0 x = 0 or 3x = –1 x = –1 3 x = 0, –1 Copyright 2011 Cambium Learning Sopris West.® All rights reserved. (continued ) Inside Algebra 3 x(x + 8) = 0 x = 0 or x + 8 = 0 x = –8 x = 0, –8 5x(2x – 1) = 0 5x = 0 or 2x – 1 = 0 x = 0 or 2x = 1 x=1 2 x = 0, 1 2 15. 27x 2 – 18x = 0 9x(3x – 2) = 0 9x = 0 or 3x – 2 = 0 x = 0 or 3x = 2 x=2 3 x = 0, 2 3 Chapter 9 • Objective 2 • PM 3 progress moNitoriNg •Do students see that the product of two numbers will be zero if and only if at least one of those numbers is zero? –3x(x – 4) x = 0 or x = 2 x = 0, 2 4x(x + 2) = 0 4x = 0 or x + 2 = 0 x = 0 or x = –2 x = 0, –2 Watch for: •Do students remember the Zero Product Property of multiplication? 3x(x + 2) Factor the polynomials and solve them using the Zero Product Property. 3.Monitor student work, and provide feedback as necessary. 1. 2x 2 + 10x = Copyright 2011 Cambium Learning Sopris West.® All rights reserved. 2.Remind students of the key term: greatest common factor (GCF). Name __________________________________________ Date __________________________ 345 Chapter 9 • Objective 2 801 Objective 2 Problem-Solving Activity Using the Length and Width of a Rectangle ★ PS 1 Use with 5-Day or 3-Day Instructional Plan. In this activity, students solve geometric problems involving area. DIRECTIONS 6.Point out that the x to the left of the parentheses in x(x + 3) is the GCF of x 2 and 3x . 1.Draw a 6 by 3 rectangle on the board. Do not include the measurements. Tell students to find the length, width, and total area in square units. Make sure students know the formula is area = length • width. Invite students to count the square units if they want to check their work. Length = 6 units, width = 3 units, area = 18 square units 2.Draw the rectangle at right on the board. Point out that the areas of the interior spaces are labeled. Ask students to think about what the dimensions are. x2 x 3 4.Tell students that if the width of the left rectangle is x units, then the width of the right rectangle x must also be x units because both rectangles have the same width. Remind students of the area formula. Point out that because the area of the right part of the rectangle is 3x and the width is x units, the length must be 3. Label the right part of the rectangle with the length. 802 Chapter 9 • Objective 2 7.Have students find the lengths and widths of more rectangles with given areas of the interior spaces. Remind students that because the left rectangle in each problem has square units, they can assume it is a square. Sample problems: 4x2 14x 3x x 3.Tell students to think of the left part of the rectangle as a square. Remind students that x if it is a square, its dimensions must be equal. Therefore, both the length and the width of the left part of the rectangle are x units long. Label the left part of the rectangle with these measurements. ★ = Includes Problem Solving 5.Point out that the area of the rectangle is x 2 + 3x because we add the small areas together to find the large area. Tell students we can double-check this area by multiplying the length, x + 3, by the width, x . Have students substitute the length and width into the area formula to find the total area of the rectangle. x(x + 3) = x 2 + 3x x2 5x length = 2x + 7 width = 2x length = x + 5 width = x 9x2 15x length = 3x + 5 width = 3x 8.Tell students to find the dimensions of more rectangles without the visual drawings. Sample problems: x 2 + 7x length = x + 7, width = x x 2 + 40x length = x + 40, width = x 2x 2 + 8x length = x + 4, width = 2x NEXT STEPS • Differentiate 5-Day and 3-Day Instructional Plans: Objective 2 Posttest, page 803—All students CHAPTER 9 Objective 2 Ongoing Assessment Objective 2 Posttest Discuss with students the key concepts in Objective 2. Following the discussion, administer the Objective 2 Posttest to all students. Using the Results • Score the posttest and update the class record card. • Provide reinforcement for students who do not demonstrate mastery of the concepts through individual or small-group reteaching of key concepts. 4x 2 + 2x 2. 30a 3b 5 + 20ab 3 3. –12m 2n 3 – 4m 3n 4. 18cd 4 – 9c 3d 2 + 36c 2d 3 5. 14x 5y 3 – 7x 3y 4 + 21x 4y 2 7. 12x 2 + 6x = 0 1. 2x(2x + 1) –4m 2n(3n 2 + m) 10ab 3(3a 2b 2 + 2) 9cd 2(2d 2 – c 2 + 4cd) Chapter 9 • Objective 2 Factor the polynomials using the greatest common factor (GCF) and the distributive property. Posttest Name __________________________________________ Date ____________________________ 7x 3y 2(2x 2y – y 2 + 3x) Solve the equations. Copyright 2011 Cambium Learning Sopris West.® All rights reserved. 6. –4x 2 + 28x = 0 –4x(x – 7) = 0 x = 0, 7 8. 5b 2 + 15b = 0 10. 12x 2 – 6x = 0 5b(b + 3) = 0 b = 0, –3 6x(2x + 1) = 0 x = 0, –1 2 9. 0 = 8a 2 – 24a 8a(a – 3) = 0 a = 0, 3 6x(2x – 1) = 0 x = 0, 1 2 Inside Algebra Chapter 9 • Objective 2 127 Chapter 9 • Objective 2 803