How can I solve a non-quadratic equation with the form y^4+4y-69=0?

[justin345]

Homework Statement

I have been solving a problem, which turned into this equation. Obviously it is not a quadratic equation. I am a little bit confused how to solve this one?

Homework Equations

The Attempt at a Solution

 

[Mark44]

It's not even an equation, so you can't solve for y. If the equation is y⁴ + 4y - 69 = 0, about the best you can do is get an approximate solution using a technique such as Newton's Method.