$\frac{-12-15}{-3}$

$\lim_{x\to-\infty}\frac{e^{3x}-1}{4x}$

$\frac{dy}{dx}\left(\left(x-y\right)^2=x+y-1\right)$

$\lim_{x\to\infty}\left(\frac{a}{b}\right)\left(1-e^{-\frac{b\:x}{m}}\right)$

$2y\left(3x^2+y^2\right)$

$\frac{x+5}{x-1}\ge x+1$

$\int_{\frac{-\pi}{2}}^{\frac{\pi}{2}}\left(\cos\left(x\right)\right)dx$