Algebra Examples

Factor $4 x^{2} - 9$

Step 1

Rewrite $4 x^{2}$ as ${(2 x)}^{2}$ .

${(2 x)}^{2} - 9$

Step 2

Rewrite $9$ as $3^{2}$ .

${(2 x)}^{2} - 3^{2}$

Step 3

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

$(2 x + 3) (2 x - 3)$