1. Opener (5 + 6) • 2 a + (b + c) + (d • e) 18k - 24 2x2 + 5x + 4y + 7
Use each named property to write an equivalent expression.
Commutative property of multiplication: 2 • (5 + 6)
Associative property of addition: (a + b) + c + (d • e)
Distributive property: 6(3k - 4)
Combine like terms: 2x x + 3y – 2x + y – 3; then name the coefficient(s) and the constant(s).
(5 + 6) • 2
a + (b + c) + (d • e)
To be used for general review
18k - 24
2x2 + 5x + 4y + 7
2, 5, 4; 7

2. Objective
□ I will be able to use subtraction and addition to solve equations.

3. Vocabulary
inverse operation – an operation that “undoes” another operation.
equation – two expressions, with the same values, set equal to one another

4. We need to isolate the variable (get the “x” by itself)
Solving an Equation
We need to find the missing value that will make this equation true:
5 + x = 10
We need to isolate the variable (get the “x” by itself)

5. The Golden Rule of Algebra
“What you do to one side of the equation, you must do to the other.”

6. Ex 1 – Using Subtraction to Solve
Solve 214 = y = y + 112
- 112
- 112
Subtract 112 from both sides
102 =
y +
Simplify
102 = y
Check your answer:
214 = y + 112
214 =
214 = 214

7. Ex 2 – Using Subtraction to Solve
Solve z = z = 10.3
- 4.7
- 4.7
Subtract 4.7 from both sides z + =
5.6
Simplify z =
5.6
Check your answer:
z = 10.3
= 10.3
10.3 = 10.3

8. Ex 3 – Using Addition to Solve
Solve x - 31 = 14. x - 31 = 14
+ 31
+ 31
Add 31 to both sides x - = 45
Simplify x = 45
Check your answer:
x - 31 = 14
= 14
14 = 14

9. Ex 4 – Using Addition to Solve
Solve 0.5 = y – = y – 1.25
+ 1.25
+ 1.25
Add 1.25 to both sides
1.75 =
y -
Simplify
1.75 = y
Check your answer:
0.5 = y
0.5 = 1.75 – 1.25
0.5 = 0.5

10. Homework
WB 2.5 (#1-19 & #24-26)