Solving Equations Inverse Operations

Find the Error
What error did the student make when solving the equation:
1/5x + 6 = 3/5x + 5
1x + 6 = 3x + 5
-2x + 6 = 5
-2x = -1
x = 1/2

• The student found an incorrect common denominator

• The student did not multiply all terms by the common denominator

• The student did not use opposite operations appropriately

• The student did not correctly eliminate the variable from one side of the equation

Find the Error
What error did the student make when solving the equation:
5x + 6 =  66
5x - 6 = 66 -6
5x = 60
5*5x= 60*5
x = 300

• The student subtracted 6 from both sides instead of adding

• Student multiplied by 5 instead of dividing by 5

• Student got the wrong answer when subtracting 66-6

• The student did not correctly eliminate the variable from one side of the equation

5x - 4 + 2x = 3

• 1

• 2

• 3

• 4

The goal of solving a one, two, or multi-step equations is to:

• Find the constant

• Find the coefficient

• Find the value of the variable

• Guess and check

0.1( x - 20 ) > 2

• x > 40

• x < 40

• x > 220

• -3m + 36
• -9m + 36
• 3m + 36

- 3( 4 - 2x) = 6

• x = 1

• x = -3 

• x = 3

We solve equations using

• fractions

• the distributive property

• inverse operations

• factors

What is the correct step to solve for the variable?

• add 15 to both sides

• add 5 to both sides

• subtract 15 from both sides

• subtract 5 from both sides

What is the correct step to solve for the variable ? x + 7 = 12

• subtract 7 from both sides.

• add 7 to both sides.

• multiply both sides by 7

• divide both sides by 7