Section 3.4

Solving Equations with Variables on Both

SidesMr. Beltz &Mr. Sparks

Goal: Solve equations that have

variables on both sides.

Basics

Get the Variables to one side (either side)

Combine Like Terms

Solve the Equation using Inverse Relationships

Remember: You always want to solve for the Variable, “X = ?”

7x + 19 = -2x + 55

+2x +2x

9x + 19 = 55

-19 -19

9x = 36

9 9

x = 4

Do the Inverse Relationship to get the Variables on the LEFT SIDE

Simply the Equation

Do the Inverse of Addition [subtraction]

Do the Inverse of Multiplication [Division]

80 – 9y = 6y

+9y +9y

80 = 15y

15 15

16 = y

3

Do the Inverse Relationship to get the Variables on the LEFT SIDE

Simply the Equation

Do the Inverse of Multiplication [Division]

3x – 10 + 4x = 5x – 7

3x + –10 + 4x = 5x + –7

7x + -10 = 5x + -7

-5x -5x

2x + -10 = -7

+10 +10

2x = 3

2 2

X= 3/2

Change – to + Opposite of the next number

Combine Like Terms

Do the Inverse Relationship to get the Variables on the LEFT SIDE

Simply the Equation

Do the Inverse of Subtraction [Addition]

Simply the Equation

Do the Inverse of Multiplication [Division]

Independent Practice

P. 152 #1-4

Independent Practice Answers

#1. x = 2

#2. y = 3

#3. x = -2

#4. x = -4

HW Assignment

P. 154

# 3-8 [all] & 17-33 [ODD]

Friday’s HW

P. 154

# 1, 2, 10-34 [EVEN], 36, 50