# How do you factor 100x^2y^2-49z^2?

$100 {x}^{2} {y}^{2} - 49 {z}^{2} = {\left(10 x y\right)}^{2} - {\left(7 z\right)}^{2} = \left(10 x y - 7 z\right) \cdot \left(10 x y + 7 z\right)$