# Is it possible to factor y=x^2 - 8x + 16? If so, what are the factors?

Mar 9, 2016

$\text{ } y = {x}^{2} - 8 x + 16 = \left(x - 4\right) \left(x - 4\right)$

#### Explanation:

Given:$\text{ } y = {x}^{2} - 8 x + 16$

Observe that $4 \times 4 = 16 \text{ and } 4 + 4 = 8$

The $8 x$ is negative so the $4 + 4 = 8 \text{ must be } - 4 - 4 = - 8$
This also works for $\left(- 4\right) \times \left(- 4\right) = + 16$

$\text{ } y = {x}^{2} - 8 x + 16 = \left(x - 4\right) \left(x - 4\right)$