1. 8.1.1 Solving Simple Equations

2. Did you know…
…there are three angles in every triangle? …you use a protractor to measure the angles of a triangle? …triangle angles are measured in degrees? …that the total value for all three angles in EVERY triangle is ALWAYS 180°?

3. What if information is missing?
Q: So if you know that all 3 angles of a triangle equal 180°, what do you do if you only know the degrees for two angles of the triangle?
A: You write a rule:
180° = angle A + angle B + angle C
Angle A = 90°
Angle B = 45°
Angle C = ?
180° = 90° + 45° + C
180° = 135° + C
45 = C
45 = C

4. Vocabulary
Addition Property of Equality – Adding the same number to each side of an equation produces an equivalent equation
If a = b
Then a + c = b + c
Subtraction Property of Equality – Subtracting the same number from each side of an equation produces an equivalent equation
Then a – c = b - c

5. Solving Addition or Subtraction Equations
Solve h + 2∏ = 3 ∏
h + 2∏ = 3 ∏
- 2 ∏ -2 ∏
h = ∏
Solve x – 7 = -6
x – 7 = -6
x = 1
Solve y = 0.5
y = 0.5
y = -2.9
Test your work by plugging your answer into the equation

6. Solve The Equations & Check Your Solutions
b + 2 = -5
g – 1.7 = -0.9
-3 = k +3
r - ∏ = ∏
t – ¼ = -¾
5.6 + z = -8

7. Vocabulary
Multiplication Property of Equality – Multiplying each side of an equation by the same number produces an equivalent equation
If a = b
Then a ∙ c = b ∙ c
Division Property of Equality – Dividing each side of an equation by the same number produces an equivalent equation
Then a ÷ c = b ÷ c

8. Solving Addition or Subtraction Equations
Solve ∏x = 3 ∏
∏x = 3 ∏
∏ ∏
x = 3
Solve -¾n = -2
-¾n = -2
-(4/3)-¾n = -(4/3)-2
n = 8/3
Test your work by plugging your answer into the equation

9. Solve The Equations & Check Your Solutions
6 ∏ = ∏x
0.09w = 1.8

10. Homework
Page 7 (#1, 12, 14, 16, 21, 25, 27, 29, 32)