# How do you simplify -3a^2b(9a^2-4b^2)?

Oct 30, 2014

In order to simplify $- 3 {a}^{2} b \left(9 {a}^{2} - 4 {b}^{2}\right)$ you would use the distributive property and multiply $- 3 {a}^{2} b$ by each of the terms in the parenthesis.
$- 3 {a}^{2} b \left(9 {a}^{2}\right)$ - $- 3 {a}^{2} b \left(4 {b}^{2}\right)$

$\left({a}^{2}\right) \left({a}^{2}\right)$ = (a)(a)(a)(a) = ${a}^{4}$ $\left(b\right) \left({b}^{2}\right)$ = (b)(b)(b) = ${b}^{3}$

$- 27 {a}^{4} b - \left(- 12 {a}^{2} {b}^{3}\right)$

Simplify the signs.

$- 27 {a}^{4} b + 12 {a}^{2} {b}^{3}$