# How do you factor #x^4 - 13x^2 - 30#?

##### 2 Answers

#### Explanation:

To factor it, first find a pair of factors of

That gives us:

The first of these quadratic factors can be considered a difference of squares:

using the difference of squares identity:

The second factor

(If you have never used

#### Explanation:

I'll call

We notice that

let

So the equation becomes:

(if you had eyes wide open, you could notice that

i.e.

So we factored the polynomial in

We notice that

If you work in

So

If you work in

So

(If you have never used