# How do you factor a^3 - ab^2 - 2a^2 + 2b^2?

Collect ${a}^{2}$ between the first and third term and $- {b}^{2}$ between the second and forth:
${a}^{2} \left(a - 2\right) - {b}^{2} \left(a - 2\right) =$ now collect $\left(a - 2\right)$:
$= \left(a - 2\right) \left({a}^{2} - {b}^{2}\right) = \left(a - 2\right) \left(a - b\right) \left(a + b\right)$