Answer:
9) x = 9
10) x = - 8
11) x = 7
Step-by-step explanation:
9)
(180 - 15x + 4) + 7x + 1 + 67 = 180
180 - 15x + 4 + 7x + 1 + 67 = 180
-15x + 4 + 7x + 1 + 67 = 0
-8x + 72 = 0
72 = 8x
x = 9
10)
100 = x + 108
100 - 108 = x
x = -8
11)
10x - 1 + 17x - 8 = 180
27x - 9 = 180
27x = 189
x = 7
