# What is the derivative of 5/x^3?

$\frac{d}{\mathrm{dx}} \frac{5}{x} ^ 3 = 5 \frac{d}{\mathrm{dx}} {x}^{-} 3 = 5 \cdot \left(- 3\right) {x}^{-} 2 = - \frac{15}{x} ^ 2$