# What is the derivative of 5 / x^4?

$\frac{d}{\mathrm{dx}} \left(\frac{5}{x} ^ 4\right) = \frac{d}{\mathrm{dx}} \left(5 {x}^{-} 4\right) = - 20 {x}^{-} 5 = - \frac{20}{x} ^ 5$