Lesson 3-3 Pages 110-114

Solving Equations by Adding or Subtracting

Lesson Check 3-2

What you will learn!1. How to solve equations by using the Subtraction Property of Equality.

2. How to solve equations by using the Addition Property of Equality.

Inverse operationInverse operationEquivalent equationsEquivalent equations

What you really need to know!

Inverse Operations: Operations that “undo” each other.

Equivalent Expressions: Expressions that have the same value.

What you really need to know!

Step 1 Identify the variable.

Step 2 To isolate the variable, add the same number to or subtract the same number from each side of the equation.

Step 3 Check the solution.

What you really need to know!

Step 1 Identify the variable.

Step 2 “Undo” the operation!

Step 3 Check the solution.

Balance!

Example 1: Solve

x + 4 = -3

x + 0 = -7x = -7

- 4 - 4

Example 2: Solve and graph solution.

x + 8 = 7

x + 0 = -1x = -1

- 8 - 8

0 1 2 3-4 -3 -2 -1-7 -6 -5 4 5 6 7

Example 3: Solve

y – 3 = -14

y + 0 = -11y = -11

+ 3 + 3

Example 3:

Movie A earned $225 million at the box office. That is $38 million less than Movie B earned. Write and solve an equation to find the amount Movie B earned.

B – 38 = 225

Example 4: Solve

B - 38 = 225

B + 0 = 263B = 263

+ 38 + 38

Movie B earned $263 million at the box office.

Example 5: Multiple-Choice

What value of x makes x – 1 = 8 a true statement?

A 9 B 7 C -7 D -9

Page 113

Guided Practice

#’s 3-11

Pages 110-112 with someone at home and study

examples!

Read:

Homework: Pages 113-114

#’s 12-44 even

#’s 50-61

Lesson Check 3-3

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Lesson 3-3

Lesson Check 3-3