# How do you factor 4c^2 – 9?

${a}^{2} - {b}^{2} = \left(a - b\right) \left(a + b\right)$
$4 {c}^{2} - 9$
$= {\left(2 c\right)}^{2} - {3}^{2}$
$= \left(2 c - 3\right) \left(2 c + 3\right)$