Expand $\left(x+1\right)\left(x+2\right)=x^2+$
$x+$
$\quad$ Factorize $x^2+3x+2=\bigl(x+$
$\bigl)\bigl(x+$
$\bigl)$
Expand $\left(x-5\right)\left(x+3\right)=x^2-$
$x-$
$\quad$ Factorize $x^2-2x-15=\bigl(x-$
$\bigl)\bigl(x+$
$\bigl)$
Expand $\left(x-4\right)\left(x-8\right)=x^2-$
$x+$
$\quad$ Factorize $x^2-12x+32=\bigl(x-$
$\bigl)\bigl(x-$
$\bigl)$
Expand $\left(x+7\right)\left(x-2\right)=$
$\quad$ Factorize $x^2+5x-14=$
Expand $\left(x-9\right)\left(x-8\right)=$
$\quad$ Factorize $x^2-17x+72=$