We shall cover this one quickly so you have time to do a brick of exercises after :D. Difference of Two Squares are the second special case of the \textbf{binomial} expansion, and come in the form $ (x + a)( x - a) $. Expanding this out with our usual \textbf{FOIL} method gives $ x^2 + \cancel{ax} - \cancel{ax} - a^2$ which just leaves $ x^2 - a^2$; how convenient!

This time I will leave the geometric intuition as an exercise, feel free to come to me before next class to explain your ideas!

\begin{exercisebox}
    \subsection{Exercises}
    \begin{enumerate}
        \item Let's Practise:
            \begin{enumerate}
                \item \((x-5)(x+5)=\)\mdots{2}
                \item \((3x-4)(3x+4)=\)\mdots{2}
                \item \((a+b)(a-b)=\)\mdots{2}
            \end{enumerate}
        \item Now back to perfect squares:
            \begin{multicols}{2}
            \begin{enumerate}
                \item \((x+1)^2=\)\mdots{2}
                \item \((x+5)^2=\)\mdots{2}
                \item \((2+x)^2)=\)\mdots{2}
                \item \((x+20)^2)=\)\mdots{2}
            \end{enumerate}
            \end{multicols}
        \item Try a mix now:
            \begin{multicols}{2}
            \begin{enumerate}
                \item \((3x-2)(3x+2)=\)\mdots{3}
                \item \((3a-4b)^2=\)\mdots{2}
                \item \((2x+3y)^2)=\)\mdots{2}
                \item \((5a+2b)(5a-2b))=\)\mdots{2}
                \item \((\frac{x}{2}+3)^2)=\)\mdots{2}
                \item \((3c-b)^2)=\)\mdots{2}
            \end{enumerate}
            \end{multicols}
    \end{enumerate}
\end{exercisebox}
