5) [tex]\bf \sqrt{3r+36}=\sqrt{-9-2r}\impliedby \textit{squaring both sides}
\\\\\\
(\sqrt{3r+36})^2=(\sqrt{-9-2r})^2\implies 3r+36=-9-2r[/tex]
solve for "r"
6)
[tex]\bf a=\sqrt{-24+10a}\impliedby \textit{squaring both sides}
\\\\\\
(a)^2=(\sqrt{-24+10a})^2\implies a^2=-24+10a
\\\\\\
a^2\quad \underline{-10a}\quad \underline{+24}=0\qquad now\qquad
\begin{cases}
-6-4\to \underline{-10}
\\\\
-6\times -4=\underline{+24}
\end{cases}\qquad thus
\\\\\\
(a-6)(a-4)=0\implies
\begin{cases}
a-6=0\implies &a=6\\\\
a-4=0\implies &a=4
\end{cases}[/tex]
