$\frac{d^3}{dx^3}2x^{-2}$

$\left(x^3.y^4\right)\left(x^5y\right)$

$\left(x+\:y\right)^7$

$\left(9x-5y\right)\left(9x-2y\right)$

$\frac{dx}{dt}=3x\:+10e^{-2t}$

$\lim_{x\to\infty}\left(x^2\cdot ln\left(\cos\:\left(\frac{1}{x}\right)\right)\right)$

$\lim_{x\to1}\left(\left(x-1\right)\cdot\ln\left(\ln\left(x\right)\right)\right)$