# How do you multiply (2x-6y)^2?

$4 {x}^{2} - 24 x y + 36 {y}^{2}$
${\left(2 x - 6 y\right)}^{2} = \left(2 x - 6 y\right) \left(2 x - 6 y\right) = 2 x \left(2 x - 6 y\right) - 6 y \left(2 x - 6 y\right)$
=$4 {x}^{2} - 12 x y - 12 x y + 36 {y}^{2}$
=$4 {x}^{2} - 24 x y + 36 {y}^{2}$