$\left(-90\right)\left(-50\right)$

$\lim_{x\to\infty}\left(\frac{\left(n+1\right)\left(x-38\right)}{n+2}\right)$

$\:\:-2b\:+\:5a\:+\:a\:-\:2\:\left[a\:+\:3b\:-\:4\:\left(a\:+b\right)\right]\:-12a\:$

$\frac{d}{dx}\left(\arcsin\left(arctan\sqrt{x}\right)\right)$

$x^2<3$

$\left(2p+q\right)^{2}$

$\int\:\:x^2\sqrt{1-x^3}dx$