Answer
$\frac{-2x^2-10x}{(x-5)^4}=\frac{-2(x^2+5x)}{(x-5)^4}$
Work Step by Step
$2x(x-5)^{-3}-4x^2(x-5)^{-4}=(x-5)^{-4}[2x(x-5)^{-3-(-4)}-4x^2]=\frac{2x(x-5)^1-4x^2}{(x-5)^4}=\frac{2x^2-10x-4x^2}{(x-5)^4}=\frac{-2x^2-10x}{(x-5)^4}=\frac{-2(x^2+5x)}{(x-5)^4}$