X~N(0,1) =>E(X)= 0, D(X)=1Y~N(1,2) =>E(Y) = 1, D(Y) =2Z=X+2YE(Z)=E(X+2Y)=E(X) +2E(Y) = 0+2=2D(Z)=D(X+2Y)=D(X) +4D(Y) = 1+8 =9
