a) 11+(-13)-(-4)+(-42)=11-13+4-42=11+4-13+42=15-55=-40
b) -21-(+15)+(-34)-(-1)=-21-15-34+1=-70+1=-69
c) (3-9+11-72)+(-9+3)=(-6+11-72)+(-6)=(-78+11)-6=-67-6=-73
d) (2-53)-(-41+79)=-51-38=-89
f) |5-9|-|27-43|+|-11+3|=|-4|-|-6|+|-8|=4-6+8=12-6=6
e) (13-20-10)-(14+7)=-17-21=-38