## 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?