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Name LESSON Date Class Problem Solving 1-4 Solving Equations by Multiplying or Dividing Write the correct answer. 1. Brett is preparing to participate in a 250-kilometer bike race. He rides a course near his house that is 1.25 km long. Write an equation to determine how many laps he must ride to equal the distance of the race. 2. The average life span of a duck is 10 years, which is one year longer than three times the average life span of a guinea pig. Write and solve an equation to determine the lifespan of a guinea pig. 3. The speed of a garden snail is onefifth that of a three-toed sloth. If a garden snail can travel at 0.03 mi/h, what is the speed of a three-toed sloth? Write an equation and solve. 4. In 2002, the movie with the highest box office sales was Titanic, which made about 2.74 times the box office sales of the number 25 movie, Mrs. Doubtfire. If Titanic made $600.8 million, about how much did Mrs. Doubtfire make? Write an equation and solve. Choose the letter for the best answer. 5. An inch is 2.54 times bigger than a centimeter. If a pencil is 18 cm long, how many inches long is it? A 45.72 in. C 15.45 in. B 20.54 in. D 7.1 in. 6. When Maria doubles a recipe, she uses 8 cups of flour. How many cups of flour are in the original recipe? F 2 cups H 8 cups J 16 cups G 4 cups 7. The depth of water is often measured in fathoms. A fathom is six feet. If the maximum depth of the Gulf of Mexico is 2395 fathoms, what is the maximum depth in feet? C 29,250 ft A 14,370 ft B 98,867 ft D 175,464 ft 8. Four times as many pet birds have lived in the White House as pet goats. Sixteen pet birds have lived in the White House. How many pet goats have there been? H 12 F 4 G 20 J 64 Copyright © by Holt, Rinehart and Winston. All rights reserved. 41 Holt Pre-Algebra Holt Middle School Math Puzzles, Twisters & Teasers 1-4 Bird-a-cology? Problem Solving 1-4 Solving Equations by Multiplying or Dividing LESSON LESSON What is the technical term for the study of birds? Write the correct answer. 2. The average life span of a duck is 10 years, which is one year longer than three times the average life span of a guinea pig. Write and solve an equation to determine the lifespan of a guinea pig. 1. Brett is preparing to participate in a 250-kilometer bike race. He rides a course near his house that is 1.25 km long. Write an equation to determine how many laps he must ride to equal the distance of the race. 1.25l ⴝ 250 Solve the equations below. Match the letter above the equations with the answers in the decoder to solve the mystery. 1. O 5x ⴝ 25 xⴝ5 3y ⴙ 1 ⴝ 10; y ⴝ 3 3. The speed of a garden snail is onefifth that of a three-toed sloth. If a garden snail can travel at 0.03 mi/h, what is the speed of a three-toed sloth? Write an equation and solve. 4. In 2002, the movie with the highest box office sales was Titanic, which made about 2.74 times the box office sales of the number 25 movie, Mrs. Doubtfire. If Titanic made $600.8 million, about how much did Mrs. Doubtfire make? Write an equation and solve. 共15兲s ⴝ 0.03; s ⴝ 0.15 mi/h 2.74m ⴝ 600.8; 4. R 6. When Maria doubles a recipe, she uses 8 cups of flour. How many cups of flour are in the original recipe? F 2 cups H 8 cups J 16 cups G 4 cups 嘷 7. The depth of water is often measured in fathoms. A fathom is six feet. If the maximum depth of the Gulf of Mexico is 2395 fathoms, what is the maximum depth in feet? C 29,250 ft A 14,370 ft 嘷 B 98,867 ft D 175,464 ft 8. Four times as many pet birds have lived in the White House as pet goats. Sixteen pet birds have lived in the White House. How many pet goats have there been? H 12 F 4 嘷 G 20 J 64 Holt Pre-Algebra Holt Middle School Math 41 Exploration Recording Sheet 1-5 Solving Simple Inequalities xⴝ6 40 boxes 2.5(25) ⴝ 62.5 2.5(40) ⴝ 100 50 boxes 11. O 2.5(30) ⴝ 75 s 10. 3 2 2 3 4 5 6 7 8 s6 13. 8g 32 greater than 0 1 2 3 4 5 6 greater than or g4 equal to not equal 16. t ⴚ 4 7 8 9 10 11 12 13 14 2–5. Situations will vary. t 11 5. 25x 500 x 20 O R N I T H O L O G Y 5 6 10 2 13 7 4 8 11 9 3 Holt Pre-Algebra Holt Middle School Math 42 2. 5(3) 5. 9 ⴙ 9 3. 15 ⴚ 7 14 16 6. 10(6) 7 65 8. 4b 8 9. n ⴚ 1 2 0 1 2 3 4 5 6 b2 0 1 2 3 4 5 6 n3 11. z ⴚ 5 5 12. 9 ⴙ p 14 6 7 8 9 10 11 12 z 10 3 4 5 6 7 8 9 p5 w 14. 2 6 15. 5z 35 8 9 10 11 12 13 14 w 12 3 4 5 6 7 8 9 z7 17. 11r 55 18. y ⴙ 14 22 0 1 2 3 4 5 6 r5 4 5 6 7 8 9 10 y8 19. An elevator has a maximum weight of 3000 pounds. How many 150-pound people can safely ride the elevator? Write and solve an inequality to answer the question. Think and Discuss 150n 3000; n 20; no more than 20 6. Discuss the strategies you used for solving the inequalities in Exercises 1–5. 20. The maximum speed of a cheetah is 70 miles per hour. A giraffe is running at a speed that is less than half the maximum speed of a cheetah. At what speed is the giraffe running? Write and solve an inequality to answer the question. Possible answer: Undo the operation being performed. 7. Explain what is meant by the phrase “solution of an inequality.” 2g 70; g 35; less than 35 mi/h. Possible answer: The possible answers that satisfy an inequality. Copyright © by Holt, Rinehart and Winston. All rights reserved. 28 a4 equal to x 14 12 0 1 2 3 4 5 6 less than or x 4. 2 7 7. a ⴙ 3 7 less than x 18 s ⴝ 11 Copyright © by Holt, Rinehart and Winston. All rights reserved. 30 boxes 2.5(50) ⴝ 125 x7 99 ⴝ 9 s xⴝ8 4. 3(7) You can use the inequality 2.5b 100, which means “2.5 times a number b is greater than or equal to 100,” to model the problem. 3. x ⴚ 6 12 yⴝ4 Solve and graph. 50 boxes 2. x ⴙ 5 12 hⴝ7 56 ⴝ 7 x 1. 3 ⴙ 8 25 or 30 boxes Give a real-world situation for each inequality and solve each inequality. 9. O 15y ⴝ 60 Use or . 40 boxes 25 boxes cⴝ9 8. H 6h ⴝ 42 10. L 1. Which of the numbers of boxes of cookies below gives Angela b. exactly $100? xⴝ3 LESSON To raise money for a school trip, Angela sells cookies for $2.50 a box. She has to raise at least $100 from the cookie sales. c. more than her goal of $100? 9c ⴝ 81 Practice A 1-5 Solving Simple Inequalities LESSON a. less than her goal of $100? 6. G 7x ⴝ 21 d ⴝ 10 5. An inch is 2.54 times bigger than a centimeter. If a pencil is 18 cm long, how many inches long is it? A 45.72 in. C 15.45 in. B 20.54 in. D 7.1 in. 嘷 y ⴝ 13 5. Y 72 ⴝ 12 x Choose the letter for the best answer. 3. T 2y ⴝ 26 yⴝ2 7. N 7d ⴝ 70 m ⴝ $219.3 million Copyright © by Holt, Rinehart and Winston. All rights reserved. 2. I 16y ⴝ 32 44 Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Pre-Algebra Holt Middle School Math Copyright © by Holt, Rinehart and Winston. All rights reserved. 114 45 Holt Pre-Algebra Holt Middle School Math Holt Pre-Algebra Holt Middle School Math