# How do you factor #2x^4-2x^2-40#?

##### 2 Answers

#### Explanation:

Factor out a

Now, to make this look more familiar, say that

Which can be factorized as follows:

Plug

You change the variable, and the result is

#### Explanation:

This is quite a remarkable polynomial here, it only has even powers! So we can change the variable, let's say

So we now have to factorise

So finally, you can factorize it as