E(aX+b) and E(ax-b)
In this tutorial I show you the meaning of these functions and how to calculate it from a probability distribution table for a discrete random variable.
Var(X+a), Var(X-a) and Var(aX)
In this tutorial I show you several formulae that you can use to work these out based on Var(X). The video includes a short exercise.
Why do these work like this?