Даю 27 баллов. Помогите

1. (-1/2)^3 = -1/8

(-1/2)^4 = 1/16

-1/8 : 1/16 = -2 (А)

2. а = 15/56  b = -187.5  c = -67.5

b < c < a (B)

3. 2x = 4/5

x = 4/5 * 1/2 = 4/10 = 2/5 (B)