# How do you factor 9a^2 - 64b^2?

May 21, 2015

The answer is $9 {a}^{2} - 64 {b}^{2} = \left(3 a + 8 b\right) \left(3 a - 8 b\right)$

Problem: $9 {a}^{2} - 64 {b}^{2}$.

This expression fits the pattern of the difference of squares:

${a}^{2} - {b}^{2} = \left(a + b\right) \left(a - b\right)$

$a = 3 a$
$b = 8 b$

$9 {a}^{2} - 64 {b}^{2} = \left(3 a + 8 b\right) \left(3 a - 8 b\right)$