1. 3.1 Addition Property of Equality (APE)

2. The Addition Property of Equality if a = b, then a + c = b + c
We can add a positive number to both sides of the equation and it will not change the equality.
We can add a negative number to both sides of the equation and it will not change the equality. (adding a negative number is the same as subtracting a positive)

3. To solve for “x” x – 8 = 11 x – 8 + 8 = 11 + 8 x = 19
Goal: get “x” alone on one side of the equation.
How: do the opposite of whatever is keeping “x” from being all by itself.
Why: by doing the opposite operation, the # on the side of the variable cancels out.
Rule: whatever you do to one side of the equation you must do to the other.
x – =
x = 19

4. Write answer with box around it
Show your work exactly like this:
Write the problem:
x + 7 = 2
Add same number to both sides of “=“:
- 7
x = -5
Write answer with box around it

5. y - 8 = -3
y = 5

6. a - 5 = -2
a = 3

7. 19 = k + 7
12 = k

8. .0
a = 3
a = 1.5

13. A number is increased by 36 is 15. Find the number.
Let x = the original number.
x + 36 = 15
- 36
- 36
x = -21

14. A number decreased by 83 is 46. Find the number.
Let x = the original number.
x - 83 = 46
+83
+83
x = 129

15. Homework: Page 116 (2-40) even How to set up Homework: 1
Homework: Page (2-40) even How to set up Homework: 1.Name, Page#, Problems Assigned 2.Must write problem 3. Show work by adding/subtracting the same amount to both sides of the equal sign 4. Show solution (box, highlight, answer column)

16. The weekly rent on an apartment was increased by $82
The weekly rent on an apartment was increased by $82. The new rental cost is $675. What is the previous rent?
Let x = the previous rent.
x + 82 = 675
- 82
- 82
x = 593