# Factoring Polynomials| Algebra| ENGG10 LE1 Problem 10

#### $81y^4-256$

SOLUTION:

We know that $81y^4=\left(9y^2\right)^2$ and $256=\left(16\right)^2$. Therefore, we are given a difference of two squares.

The factors are

$=\left(9y^2-16\right)\left(9y^2+16\right)$

The factor $\left(9y^2-16\right)$ is also difference of two squares. So, we can further factor out the factors as

$=\left(3y+4\right)\left(3y-4\right)\left(9y^2+16\right)$