1. Г. -9

2.

1) p-(p-a) = p-p+a = a

2) b+(-b+3) = b-b+3 = 3

3) (x+2)-(x+7) = x+2-x-7 = -5

3. (1,2-4 целых 3/8) -(5 целых 1/16 - 1,8) = 1,2+1,8-4 целых 6/16-5 целых 1/16 = 3-9 целых 7/16 = 6 целых 7/16

4. 25+(-15)-(-35)-(+55)= -10