$-40cd+16c^2+25d^2$

$\frac{4}{9a^2}-\frac{2}{3a}+\frac{1}{4}$

$\frac{x\left(x+3\right)}{x^2+3}$

$\lim_{x\to0}\left(\frac{x^2-2x-8}{x-4}\right)$

$\int_2^{\infty}\left(\frac{lnx}{\left(x\right)}\right)dx$

$3\left(17\right)-19$

$\lim_{x\to\infty}\left(x\left(\sqrt{x^2+2x}-x-1\right)\right)$