Download Ch. 2-3 Online Notes

Name
Class
Lesson 2-3 Date
Solving Multi-Step Equations
Lesson Objective
Common Core State Standards
To write and solve multi-step equations
Expressions and Equations: 8.EE.7, 8.EE.7.b
Example
2c 1 2 1 3c 5 12
2c 1 3c 1 2 5 12
5c 1 2 5 12
← Commutative Property of Addition
← Combine like terms.
5c 1 2 2 2 5 12 2 2 ← Subtract 2
5c 5
10 5c
10
5
5
5
← Simplify.
← Divide each side by 5 .
← Simplify.
c5 2 Check 2c 1 2 1 3c 5 12
  1 2 1 3 2  0 12
2 2
from each side.
← Substitute 2 for c.
© Pearson Education, Inc., publishing as Pearson Prentice Hall.
All rights reserved.
1 Simplifying Before Solving an Equation Solve 2c 1 2 1 3c 5 12.
12 5 12 ✓ ← The solution checks.
Quick Check
1. Solve 215 5 5b 1 12 2 2b 1 6. Check the solution.
211
2 15 5 5(211) 1 12 2 2(211) 1 6
215 5 215
20
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Course 3 Lesson 2-3
Daily Notetaking Guide
10/10/12 4:29 PM
Name
Class
Date
Example
2 Using the Distributive Property Eight cheerleaders set a goal of selling
424 boxes of cards to raise money. After two weeks, each cheerleader has
sold 28 boxes. How many more boxes must each cheerleader sell?
A. 15 boxes B. 25 boxes C. 50 boxes D. 53 boxes
Words
All rights reserved.
8 cheerleaders 
1

additional boxes
5 424 boxes
per cheerleader
Let x 5 the number of additional boxes per cheerleader.
8  Equation
8(28 1 x) 5 424
224 1 8x 5 424

28 224 2 224 1 8x 5 424 2 224 8x 5 200
8x
200
5
8
8
x5
Each cheerleader must sell
© Pearson Education, Inc., publishing as Pearson Prentice Hall.
boxes per
 28cheerleader
25 1 
x 5 424
← Distributative Property
← Subtract 224 from each side.
← Simplify.
← Divide each side by 8 .
← Simplify.
25 more boxes. The correct answer is choice B .
Quick Check
2. Class Trips Your class goes to an amusement park. Admission is $10
for each student and $15 for each chaperone. The total cost is $380.
There are 12 girls in your class and 6 chaperones on the trip. How many
boys are in your class?
6 ? 15 1 10(x 1 12) 5 380
17 boys
Daily Notetaking Guide
441198_C3_Ch2_WKbk_Ver-1.indd 21
Course 3 Lesson 2-3
21
10/10/12 4:29 PM