# How do you solve #64x^4-81>0#?

##### 1 Answer

#### Answer:

and

#### Explanation:

Let's first see that all of the terms are perfect squares:

If we assign

which can be factored as

Substituting back in:

And now let's solve the inequality. First we change the

we get:

as points of significance.

Working with the roots, if we set

and so our solution lies outside the points (as opposed to inside), and so the final answer is:

and