121

$\left|2a\right|-\left|3a\right|$
$\left|a\right|$

$\left|-2a\right|+\left|3a\right|$

$5\left|a\right|$

$\left|a^2+1\right|+\left|a\right|^2-\left|3a^2\right|$
$1-a^2$

$\left|a-2\right|^2$
$\left(a-2\right)^2$