$\lim_{x\to4}\frac{x^3-4x^2}{x^2-16x}$

$x^2+2x+15$

$\left(e^{\left(2\cdot y\right)}-y\cdot cos\left(x\cdot y\right)\right)\:+\:\left(2x\cdot e^{\left(2\cdot y\right)}-x\cdot cos\left(x\cdot y\right)\:+\:2y\right)y'=0$

$\int\left(3x^{-4}\left(\frac{1}{x^3}+2\right)\right)dx$

$5\cdot\left(-2\right)-4\cdot\left(-2-5\right)$

$li\lim_{x\to1}\frac{\sqrt{x}-1}{\sqrt{x+3}-2}$

$\left(48-x\right)^2$