Answer:
1) 44=t-72
Add 72 to both sides and you'll get [116=t]
2) 18+z=40
Subtract 18 from both sides to get [z=22]
3) 18-(-f)=91
18-(-f)= means 18+f=91
Subtract 18 from both sides to get f=73
4) -57=y-2
Add 2 to both sides to get -55=y
5) 14=d+(-10)
14=d+(-10) means 14=d-10
Add 10 to both sides to get 24=d