Say I am given two random variables A and B along with their expected values, expected value of their squares and variances:
$$ E[A] = 5, E[B] = 2, Var(A) = 10, Var(B) = 12, E[A^2] = 20, E[B^2] = 16 $$
I am given two random variable $C = AB$ and $D = A(2+B)$ and asked to find the expected value and variance of the random variable C.
Am I safe to assume that the only required step is to substitute values of $AB$ in $C$ for the Expected values and variance respectively or am I missing something?