2-Step Equations

What??? I just learned 1-step!

Relax. You’ll use what you already know to solve 2-step equations.

Solving Two-Step Equations

To find the solution to an equation we must isolate the variable. In other words, get the variable on one side of the equation by itself.

We isolate the variable by performing operations that will eliminate (cancel) the other numbers from the expression.

Solving Two-Step Equations

We have seen how to eliminate a constant (Addition Property of Equality) & how to eliminate a coefficient (Multiplication Property of Equality).

What if an equation has both a constant and a coefficient to be eliminated?

This is called a Two-Step Equation.

STEP 1

The first step will always be either adding or

subtracting. (Think: Order of Operations backwards)

STEP 2

The second step will always be either

multiplying or dividing.

8x + 5 = 61This problem has addition, so we need to subtract first.

- 5 - 5

Whatever we do on one side, we have to do on the other.

8x 56=

EX1)

This problem has multiplication, so we need to divide now.

8 8

x = 7 8x + 5 = 618(7) + 5 = 6156+ 5 = 61

61= 61

Check

EX2) 3a - 8 = 4This problem has subtraction, so we need to add first.+ 8 + 8

3a 12=3 3a = 4

This problem has multiplication, so we need to divide now. 3a - 8 = 4

3(4) - 8 = 412 - 8 = 4 4= 4

Check

EX3) z + 2 = 266

This problem has addition, so we need to subtract first.- 2 - 2

24=z6

This problem has division, so we need to multiply now.

z =144

6 • • 6 z + 2 = 266

144 + 2 = 26 624 + 2 = 26

26 = 26

Check

EX4) m - 10 = 155

This problem has subtraction, so we need to add first.+10 +10

25=m5

This problem has division, so we need to multiply now.

m = 125

5 • • 5m - 10 = 155

125 - 10 = 15 525 - 10 = 15

15= 15

Check

Assignment Page 5371-6 , 9-11

show work on a separate sheet of

paper

Notes start here

2-Step Equations

Date ______________

8x + 5 = 61EX1)

EX2) 3a - 8 = 4

EX3) z + 2 = 266

EX4) m - 10 = 155