Answer:
Explanation:
Exercise 11
4x + 3 = 9x - 37
9x - 4x = 3 + 37
5x = 40
x = 40/5
x = 8
m 1 = 4 · 8 + 3 = 32 + 3 = 35°
m 2 = 180 - (120 + 35) = 180 - 155 = 25°
m 3 = 180 - 60 = 120°
m 4 = 60°
m 5 = 60°
m 6 = 60°
m 7 = 180 - (120 + 35) = 180 - 155 = 25°
m 8 = 180 - 60 = 120°
m 9 = 9 · 8 - 37 = 72 - 37 = 35°
Exercise 12
3x + 18 = 7x - 58
7x - 3x = 58 + 18
4x = 76
x = 76/4
x = 19°
m A = 3 · 19 + 18 = 57 + 18 = 75°
m B = 7 · 19 - 58 = 133 - 58 = 75°
m C = 2 · 19 - 8 = 38 - 8 = 30°
Exercise 13
8x - 17 = 5x + 1
8x - 5x = 17 + 1
3x = 18
x = 18/3
x = 6°
m Q = 8 · 6 - 17 = 48 - 17 = 31°
m S = 5 · 6 + 1 = 30 + 1 = 31°
m R = 19 · 6 + 4 = 114 + 4 = 118°
EXERCISE 14
7x -37 = 3x + 23
7x - 3x = 37 + 23
4x = 60
x = 60/4
x = 15
LM = 7 · 15 - 37 = 105 - 37 = 68
KM = 3 · 15 + 23 = 45 + 23 = 68
KL = 9 · 15 - 40 = 135 - 40 = 95
Exercise 15
13x - 21 = 8x - 6
13x - 8x = 21 - 6
5x = 15
x = 15/5
x = 3
XY = 13 · 3 - 21 = 39 - 21 = 18
YZ = 8 · 3 - 6 = 24 - 6 = 18
XZ = 3 + 4 = 7