Chapter 5.2, Problem 2MC

We use the equation ${\left(a+b\right)}^2=a^2+2ab+b^2$ to find a similar equation for ${\left(a-b\right)}^2$.Supply any missing steps or Justifications.

$\begin{array}{rll}{\left(a-b\right)}^2& =& {\left[a+\left(-b\right)\right]}^2\\ & =& a^2+2a\left(-b\right)+{\left(-b\right)}^2\\ & =& a^2-2ab+b^2\end{array}$ $\begin{array}{ccc}{\left(a-b\right)}^2& =& [{\left(a+\left(-b\right)\right]}^2\end{array}{a}^2-2a\left(-b\right)+b^2\\ a^2-2ab+b^2$