Factor 9d^2-49

$9 d^{2} - 49$

Step 1

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

${(3 d)}^{2} - 49$

Step 2

Rewrite $49$ as $7^{2}$ .

${(3 d)}^{2} - 7^{2}$

Step 3

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 3 d$ and $b = 7$ .

$(3 d + 7) (3 d - 7)$