## Proof that an expression is divisible by a certain integer (power type)

#### Prove the following:

- 3
^{2n}– 1 is divisible by 8

or 3^{2n}– 1 is a multiple of 8

#### The method of induction:

- Start by proving that it is true for n=1, then assume true for n=k and prove that it is true for n=k+1. If so it must be true for all positive integer values of n.

## Proof that an expression is divisible by a certain integer (non-power type)

#### Prove the following:

- is divisible by 3