Factor 81-64v^2

$81 - 64 v^{2}$

Step 1

Rewrite $81$ as $9^{2}$ .

$9^{2} - 64 v^{2}$

Step 2

Rewrite $64 v^{2}$ as ${(8 v)}^{2}$ .

$9^{2} - {(8 v)}^{2}$

Step 3

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 9$ and $b = 8 v$ .

$(9 + 8 v) (9 - (8 v))$

Step 4

Multiply $8$ by $- 1$ .

$(9 + 8 v) (9 - 8 v)$