Step-by-step explanation:
[tex]\dfrac{-14x^3}{x^3-5x^4}\qquad\text{where}\ x^3-5x^4\neq0\\\\x^3-5x^4\neq0\qquad\text{distributive}\\\\x^3(1-5x)\neq0\iff x^3\neq0\ \wedge\ 1-5x\neq0\\\\x\neq0\ \wedge\ x\neq\dfrac{1}{5}\\\\\dfrac{-14x^3}{x^3(1-5x)}\qquad\text{cancel}\ x^3\\\\=\dfrac{-14}{1-5x}\qquad\text{where}\ x\neq\dfrac{1}{5}[/tex]
