C = -8 + 6 -4 -10 +6 -3

C = -25 + 12

C = - 13

D = 7 + 3 -9 + 5 - 4 - 8

D = 15 -21

D= -6

E = - 21 + 134 - 45 - 134 + 28  + 45

E= - 200 + 207

E = 7

F = 37 - 74 - 18 + 74 - 37 + 40

F = 151 - 129

F = 22