Pre-Algebra Examples

$121 a^{2} - b^{2}$

Step 1

Rewrite $121 a^{2}$ as ${(11 a)}^{2}$ .

${(11 a)}^{2} - b^{2}$

Step 2

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 11 a$ and $b = b$ .

$(11 a + b) (11 a - b)$