$\frac{2}{3x}-\frac{6}{x^2}+\frac{7}{x^3}$

$\frac{10x^2y^3}{-5x^3y^2}$

$u^2+42u=0$

$\left(-2x^4y^0\right)\left(-10x^{-4}\right)$

$\lim\:_{x\to\:-4}\left(\frac{3}{x^2+3x-4}\right)$

$\int\left(x+1\right)^2\sqrt[3]{1-x}dx$

$\left(\csc\left(a\right).\sec\left(a\right)\right)$