X and Y are independent random variables X is uniform over [1,5] Y is exponential with λ=2 We?

... like to study Z=(Y/2)-(1/X)
Let A=Y/2 and B=1/X so that Z=A-B
1/ Express E(Z) in terms of E(A) and E(B)
2/ Express V(Z) in terms of V(A) and V(B)
3/ Calculate E(A) and V(A)
4/ Calculate E(B) and V(B)
5/ Calculate E(Z)
6/ Calculate V(Z)