$rs+4st$

$\frac{4x}{\sqrt{2x}}$

$\frac{1}{8\:}xy+\frac{1}{4}y+\frac{3}{16}xy$

$\frac{x^2-6x-4}{x-1}$

$\int\frac{8x-3}{x\left(x^2+4\right)^2}dx$

$\left[\frac{\left(-5\cdot4\right)-\left(-2+4\right)}{15+\left(-6\right)-\left(-2\right)}\right]+\left[\frac{7\cdot\left(-4\right)}{10-\left(3\right)}+\frac{2+\left(-10\right)}{-4}\right]-\left[\frac{5+\left(-3\right)-\left(-2\cdot3\right)}{\left[4\cdot\left(-3\right)\right]+4}\right]$

$\frac{dy}{dx}\left(x^{-\frac{7}{8}}-y^{-\frac{7}{8}}=9\right)$