Answer:
1. x = 10
2. x = 8
3. x = 7
Explanation:
1. Sum of Angles in a triangle = 180
(6x + 3) + (5x - 7) + 74 = 180
11x - 4 + 74 = 180
11x + 70 = 180
Subtract 70 from both sides
11x = 110
Divide both sides by 11
x = 10
2. (8x + 1) + (7x + 14) + 45 = 180
15x + 15 + 45 = 180
15x + 60 = 180
Subtract 60 from both sides
15x = 120
Divide both sides by 15
x = 8
3. We first have to get the 3rd angle: 180 - Exterior angle = 3rd angle
180 - 118 = 62
Now we can find the value of x
10x + (6 + 6x) + 62 = 180
16x + 68 = 180
Subtract 68 from both sides
16x = 112
Divide both sides by 16
x = 7