# How do you find the product (9-2y)^2?

Feb 9, 2018

$4 {y}^{2} - 36 y + 81$

#### Explanation:

${\left(9 - 2 y\right)}^{2} = \left(9 - 2 y\right) \left(9 - 2 y\right)$

$\text{each term in the second factor is multiplied by each term}$
$\text{in the first factor}$

$\Rightarrow \left(\textcolor{red}{9 - 2 y}\right) \left(9 - 2 y\right)$

$= \textcolor{red}{9} \left(9 - 2 y\right) \textcolor{red}{- 2 y} \left(9 - 2 y\right)$

$\text{distributing gives}$

$= 81 - 18 y - 18 y + 4 {y}^{2}$

$= 4 {y}^{2} - 36 y + 81$