1. Solving 2-Step Variable Equations

2. What??? Relax!! You’ve already learned 1-step!
You’ll use what you already know to solve 2-step equations.

3. STEP 1
The first step – Simplify anything you may need to on each side of the equal sign. Look for things like the distributive property and like terms.

4. STEP 2
The second step – figure out the order that you would DO to solve if you knew the value of the variable.

5. STEP 3
The third step – is to UNDO those steps by working in reverse order using inverse operations! + - ÷ •

6. Whatever we do on one side, we have to do on the other.
Let’s try a problem.
Distributive?
Like Terms?
8x + 5 = 61
So to UNDO:
- 5 then…
÷ 8
- 5
- 5
We would first DO:
· 8 then…
+ 5 so… = 56 8x
Whatever we do on one side, we have to do on the other.

7. Now, Step 2.
8x = 56
Whatever we do on one side, we have to do on the other.
This problem has multiplication, so we need to divide now. 8 8 x 7 =

8. Whatever we do on one side, we have to do on the other.
Let’s try a problem.
Distributive?
Like Terms?
-5x + 3 = 38
- 3
- 3
UNDO in reverse…
- 3
÷ (-5)
DO originally…
· (-5)
+ 3 = 35
-5x
Whatever we do on one side, we have to do on the other.

9. Now, Step 2.
-5x = 35
Whatever we do on one side, we have to do on the other.
This problem has multiplication, so we need to divide now. -5 -5 x -7 =

10. Let’s try another problem.
Distributive?
Like Terms?
+ 9
+ 9
DO originally…
÷ (-4)
- 9
UNDO in Reverse…
+ 9 = 40
· (-4)
Whatever we do on one side, we have to do on the other.

11. Now, Step 2.
This problem has division, so we need to multiply now. a =
-160
Whatever we do on one side, we have to do on the other.

12. Let’s try another problem.
Distributive?
Like Terms?
DO originally…
- 8
÷ 3
UNDO in
reverse…
· 3
+ 8
a - 8 = 12
Whatever we do on one side, we have to do on the other.

13. Now, Step 2.
a - 8 = 12
+ 8
+ 8 a 20 =
Whatever we do on one side, we have to do on the other.

14. Whatever we do on one side, we have to do on the other.
Let’s try a problem.
Distributive?
Like Terms?
-3x + 5x - 3 = 9
2x - 3 = 9
UNDO in reverse…
+ 3
÷ 2
DO originally…
· 2
- 3
+ 3
+ 3 2x = 12
Whatever we do on one side, we have to do on the other.

15. Now, Step 2.
2x = 12 2 2 x = 6
Whatever we do on one side, we have to do on the other.

16. Whatever we do on one side, we have to do on the other.
Let’s try a problem.
Distributive?
Like Terms?
2(-3x – 14) = - 4
-6x - 28 = - 4
UNDO in reverse…
+ 28
÷ (-6)
DO originally…
· (-6)
- 28
+ 28
+ 28
-6x = 24
Whatever we do on one side, we have to do on the other.

17. Now, Step 2.
-6x = 24 -6 -6 x =
- 4
Whatever we do on one side, we have to do on the other.

18. Now you try some problems.
Set up the DO/UNDO chart for each question. Solve and show all your work!
7f + 5 = 40

19. Now you try some problems.
Set up the DO/UNDO chart for each question. Solve and show all your work!
7f + 5 = 40
t=5
t = 186
y = -80
m = 100
x = -21
x = 3