How do I add or subtract independent random variables (R.Vs) when given their individual expectations and variance? I'm a student in high school and I haven't covered distributions yet, so please try not to use them.
Example, R.Vs A, B & C
$E(A)= 35\;\;\ Var(A)=8\\ E(B) = 25\;\;\;\; Var(B)=9\\$
Calculate the expectation and variance of:
$A + 2B$