# How do you find (d^2y)/(dx^2) given x^2-xy=5?

Sep 20, 2016

$- \frac{10}{x} ^ 3$

#### Explanation:

From ${x}^{2} - x y = 5$ we know that

$y = \frac{{x}^{2} - 5}{x}$ then

$\frac{\mathrm{dy}}{\mathrm{dx}} = 1 + \frac{5}{x} ^ 2$ and following

$\frac{{d}^{2} y}{{\mathrm{dx}}^{2}} = - \frac{10}{x} ^ 3$