1. Equation y + 5 y + 5 = 20 Expressions
We can evaluate an expression, when given the value of the variable.
Expressions
y + 5
Equation
y + 5 = 20
We can solve an equation to find the value of the variable.

2. 1. The '=' sign divides the equation into two parts.
y + 5 = 20
- 5
- 5
2. Whatever you do on one side of the equal sign, must be done to the other side. y = 15
3. You must isolate the variable by using the inverse operation.

3. 1. The '=' sign divides the equation into two parts.
2. Whatever you do on one side of the equal sign, must be done to the other side.
3. You must isolate the variable by using the inverse operation.
m + 6 = 8
- 6
- 6 m = 2

4. 1. The '=' sign divides the equation into two parts.
2. Whatever you do on one side of the equal sign, must be done to the other side.
3. You must isolate the variable by using the inverse operation.
9 + w = 20
- 9
- 9 w = 11

5. 1. The '=' sign divides the equation into two parts.
2. Whatever you do on one side of the equal sign, must be done to the other side.
3. You must isolate the variable by using the inverse operation.
r + 6 = 2
- 6
- 6 r =
- 4

6. Practice - Solve each equation. Show all work. 1) 12 + y = 20
-12
-12 -7 -7 -8 -8
c = -5
y = 8
8 = r

7. 3) c + 8 = 1 Do Now - Solve each equation. Show all work.
1) m = 32
2) = 7 + r
3) c + 8 = 1
-17
-17 -8 -8 -7 -7
c = -7
m = 15
-16 = r

8. 1. The '=' sign divides the equation into two parts.
2. Whatever you do on one side of the equal sign, must be done to the other side.
3. You must isolate the variable by using the inverse operation.
r -7 = 2
+ 7
+ 7 r = 9

9. Solve each equation.
1) r - 9 = 4
2) -12 = y - 3 +3 +9 +3 +9 r
=13 -9 =y

10. Solve each equation.
1) r - 8 = 2
2) -15 = y - 4

11. Practice - Solve each equation. Show all work.

12. Practice - Solve each equation. Show all work.
4) m = 20
6) e + (-6) = -12
5) y- (-5)= 10