# How do you use the difference of two squares formula to factor 2(y-4)^2 - 50?

Aug 7, 2018

$2 \left(y - 9\right) \left(y + 1\right)$

#### Explanation:

$\text{take out a "color(blue)"common factor } 2$

$= 2 \left[{\left(y - 4\right)}^{2} - 25\right]$

${a}^{2} - {b}^{2} = \left(a - b\right) \left(a + b\right) \leftarrow \textcolor{b l u e}{\text{difference of 2 squares}}$

$\text{with "a=y-4" and } b = 5$

=2((y-4-5))((y-4)+5))

$= 2 \left(y - 9\right) \left(y + 1\right)$