# How do you factor 15a^2b - 10ab^2?

$15 {a}^{2} b - 10 a {b}^{2} = 5 a b \left(3 a - 2 b\right)$
Both of the terms are divisible by $5 a b$, so separate that out as a factor:
$15 {a}^{2} b - 10 a {b}^{2} = 5 a b \left(3 a\right) - 5 a b \left(2 b\right) = 5 a b \left(3 a - 2 b\right)$