Pre-Algebra Examples

$169 x^{2} - 225 y^{2}$

Step 1

Rewrite $169 x^{2}$ as ${(13 x)}^{2}$ .

${(13 x)}^{2} - 225 y^{2}$

Step 2

Rewrite $225 y^{2}$ as ${(15 y)}^{2}$ .

${(13 x)}^{2} - {(15 y)}^{2}$

Step 3

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 13 x$ and $b = 15 y$ .

$(13 x + 15 y) (13 x - (15 y))$

Step 4

Multiply $15$ by $- 1$ .

$(13 x + 15 y) (13 x - 15 y)$