# How do you factor 4a^2-25?

Jun 19, 2017

See a solution process below:

#### Explanation:

This is a special form of the quadratic:

$\left(x + y\right) \left(x - y\right) = {x}^{2} - {y}^{2}$

Substitute:

$2 a$ for $x$

$5$ for $y$

Giving:

$\left(2 a + 5\right) \left(2 a - 5\right) = {\left(2 a\right)}^{2} - {5}^{2}$

$\left(2 a + 5\right) \left(2 a - 5\right) = 4 {a}^{2} - 25$