# How do you factor 25a^2-36b^2?

Using the identity ${a}^{2} - {b}^{2} = \left(a - b\right) \cdot \left(a + b\right)$ we have that
$25 {a}^{2} - 36 {b}^{2} = {\left(5 a\right)}^{2} - {\left(6 b\right)}^{2} = \left(5 a - 6 b\right) \cdot \left(5 a + 6 b\right)$