\begin{enumerate}
\begin{multicols}{2}
\item 
$\begin{aligned}[t]
A & =(x+2)(x+3)\\
  & = x^2+3x+2x+6\\
\Aboxed{A & = x^2+6x+6}
\end{aligned}$

\item 
$\begin{aligned}[t]
B & =(3x+2)(5x+3)\\
  & = 15x^2+9x+10x+6\\
\Aboxed{B & = 15x^2+19x+6}
\end{aligned}$

\item 
$\begin{aligned}[t]
C & =(3-5x)(2x-7)\\
  & = 6x-21-10x^2+35x\\
\Aboxed{C & = -10x^2+41x-21}
\end{aligned}$

\item 
$\begin{aligned}[t]
D & =(5x-4)(-3x-2)\\
  & = -15x^2-10x+12x+8\\
\Aboxed{D & = -15x^2+2x+8}
\end{aligned}$

\item
$\begin{aligned}[t]
E & =(4x-1)(2x+4)+(2x-1)(5x+3)\\
& = (8x^2+16x-2x-4)+(10x^2+6x-5x-3)\\
\Aboxed{E & = 18x^2 + 15x-7}
\end{aligned}$

\item
$\begin{aligned}[t]
F & =(x-4)(x+3)-2(x+1)(x-2)\\
& = (x^2+3x-4x-12)-2(x^2-2x+x-2)\\
& = x^2-x-12-2x^2+2x+4\\
\Aboxed{F&=-x^2+x-8}
\end{aligned}$

\item
$\begin{aligned}[t]
G & =(x+5)(2x-1)-5(x+7)(x+1)\\
& = (2x^2-x+10x-5)-5(x^2+x+7x+7)\\
& = 2x^2+9x-5-5x^2-40x-35\\
\Aboxed{G&=-3x^2-31x-40}
\end{aligned}$
\end{multicols}
\end{enumerate}