Question

Simplify: $2l^3+432m^3$

Answer 1

$2l^3+432m^3=2(l^3+216m^3)$

$=2(l^3+{\left(6m\right)}^3)$

$=2(l+6m)(l^2+{\left(6m\right)}^2-l\cdot 6m)$ $[$By using $a^3+b^3=\left(a+b\right)\left(a^2+b^2-ab\right)]$

$=2(l+6m)(l^2+36m^2-6lm)$