# How do you find the product of (a-4)^2?

Apr 12, 2018

See a solution process below:

#### Explanation:

Use this rule for this special case of quadratics:

$\left(\textcolor{red}{x} - \textcolor{b l u e}{y}\right) \left(\textcolor{red}{x} - \textcolor{b l u e}{y}\right) = {\textcolor{red}{x}}^{2} - 2 \textcolor{red}{x} \textcolor{b l u e}{y} + {\textcolor{b l u e}{y}}^{2}$

Let:

$\textcolor{red}{a}$ replace $\textcolor{red}{x}$

$\textcolor{b l u e}{4}$ replace $\textcolor{b l u e}{y}$

${\left(\textcolor{red}{a} - \textcolor{b l u e}{4}\right)}^{2} \implies$

$\left(\textcolor{red}{a} - \textcolor{b l u e}{4}\right) \left(\textcolor{red}{a} - \textcolor{b l u e}{4}\right) \implies$

${\textcolor{red}{a}}^{2} - \left(2 \cdot \textcolor{red}{a} \cdot \textcolor{b l u e}{4}\right) + {\textcolor{b l u e}{4}}^{2} \implies$

${a}^{2} - 8 a + 16$