8.1.1 Solving Simple Equations

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°?

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 - 135 - 135 45 = 0 +C 45 = C

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

Solving Addition or Subtraction Equations Solve h + 2∏ = 3 ∏ h + 2∏ = 3 ∏ - 2 ∏ -2 ∏ h = ∏ Solve x – 7 = -6 x – 7 = -6 +7 +7 x = 1 Solve y + 3.4 = 0.5 y + 3.4 = 0.5 - 3.4 -3.4 y = -2.9 Test your work by plugging your answer into the equation

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

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

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

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

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