Factor 9a^2-64

$9 a^{2} - 64$

Step 1

Rewrite $9 a^{2}$ as ${(3 a)}^{2}$ .

${(3 a)}^{2} - 64$

Step 2

Rewrite $64$ as $8^{2}$ .

${(3 a)}^{2} - 8^{2}$

Step 3

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 3 a$ and $b = 8$ .

$(3 a + 8) (3 a - 8)$