1. Equation Invasion
Objective: I can solve two-step equations using the opposite operation to determine the value of an unknown variable.

2. What is the Big Idea? What are two-step equations?
How are they different that one- step equations?
Can I still use the opposite operation to isolate the variable?

3. One-Step Review-o-Rama
x - 67 = 72
First, we isolate the variable by using the opposite operation.
+ 67
+ 67
Then, whatever we do to one side, we have to do to the other.
x = 139
Next, we re-write our equation.
= 72
Finally, we check our work by plugging in our answer to our original equation.

4. Share out with your neighbor!
What do YOU think?
How do you think two-step equations are different than one-step equations?
Share out with your neighbor!

5. Step 1: Get rid of the number that is NOT connected to the variable.
Step by Step
3x + 14 = 47
- 14
Step 1: Get rid of the number that is NOT connected to the variable.

6. Step 2: Whatever you do to one side, YOU HAVE TO DO TO THE OTHER!
Step by Step
3x + 14 = 47
- 14
- 14
Step 2: Whatever you do to one side, YOU HAVE TO DO TO THE OTHER!

7. Step 3: Re-write your equation.
Step by Step
3x + 14 = 47
- 14
- 14
3x = 33
Step 3: Re-write your equation.

8. Step 4: Isolate the variable using the OPPOSITE OPERATION.
Step by Step
3x = 33
Hey! This is just like one-step equations now!! ÷3
Hint: The 3 is connected to the variable with multiplication.
Step 4: Isolate the variable using the OPPOSITE OPERATION.

9. Step 5: Whatever I do to one side, I HAVE TO DO TO THE OTHER!
Step by Step
3x = 33 ÷3 ÷3
Step 5: Whatever I do to one side, I HAVE TO DO TO THE OTHER!

10. Step 6: Re-write your equation!
Step by Step
3x = 33 ÷3 ÷3
x = 11
Step 6: Re-write your equation!

11. Step by Step
3x + 14 = 47
x = 11
3(11) + 14 = 47
Step 7: Check your work, by plugging in your answer into your original equation.

12. h/ = 40
-34
-34
Always get rid of the number NOT attached to the variable FIRST
Whatever I do to one side, I have to do to the other!
h/12 = 6
x 12
x 12
Re-write your equation!
h = 72
Solve like it is a one-step, don’t forget to check!

13. h/ = 40
h = 72
72/ = 40

14. Slate Time
4x - 15 = 25
x= 10
23 + 9x = 77
x= 6

15. f/ =20
f=40
Challenge
7r + 12 = 15
r =3/7

16. ...To use your common sense and problem solving skills!