1. Solving One Step Equations with Addition and Subtraction

2. Solving One Step Equations with Addition and Subtraction
Definition:
Inverse Operations - Are opposite operations. Adding is the inverse of subtracting and subtracting is the inverse of adding.
The goal when solving equations is to isolate the variable.
We isolate the variable by completing inverse operation(s).
Remember, what you do to one side of the equation you MUST do to the other!

3. Solving One Step Equations with Addition and Subtraction
Inverse Actions and Operations
What is the inverse of putting items in a box?
What is the inverse of tying your shoes?
What is the inverse of doing your homework?
What is the inverse of multiplication?

4. Solving One Step Equations with Addition
Example 1
x + 22 = 53
x = 31
Check:
Does = 53?
53 = 53
Example 2
41 = 17 + y
- 17 – 17___
24 = y or
y = 24
Check:
Does 41 = ?
41 = 41
Original equation
Original equation
Subtract 62 from BOTH sides to isolate x.
Subtract 17 from BOTH sides to isolate y.
Solution
Solution
Check your work to see if your answer is correct!
Check your work to see if your answer is correct!
Yes, it does
Yes, it does

5. Solving One Step Equations with Addition and Subtraction
Try these: Show all work and check your solutions.
1.) x + 16 = ) 21 = a - 13
3.) a + 33 = ) 45 = d - 11

6. Solving One Step Equations with Subtraction
Example 1
p – 2 = 5
p = 7
Check:
p - 2 = 5
Does = 5?
5 = 5
Example 2
40 = x - 11
40 = x – 11
51 = x or
x = 51
Check:
Does 40 = 51 – 11?
40 = 40
Original equation
Original equation
Add 2 to BOTH sides to isolate p.
Add 11 to BOTH sides to isolate x.
Solution
Solution
Check your work to see if your answer is correct!
Check your work to see if your answer is correct!
Yes, it does
Yes, it does

7. Solving One Step Equations with Addition and Subtraction
Real-Life Application
Some surfers recommend that the length of a beginner’s surfboard be 14 inches greater than the surfer’s height. If a surfer was surfing with a surfboard that was 82 inches long, how tall is the surfer? Set up and solve an equation to find the answer.
Verbal Story
Algebraic Equation

8. Solving One Step Equations with Addition and Subtraction
Real-Life Application
When Theodore Roosevelt became president of the United States, he was 42 years old. He was 27 years younger than Ronald Reagan when Reagan became president. How old was Reagan when he became president? Set up and solve an equation to find the answer.
Verbal Story
Algebraic Equation