$\frac{r-5}{r+3}.\frac{r+4}{r+4}$

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

$\lim_{x\to0}\left(1\:+\:\sin\left(x\right)^{\frac{1}{x}}\right)$

$\int_{\frac{\pi}{6}}^{\frac{5\pi}{6}}\left(1+2\sin\left(x\right)\right)^2dx$

$\lim_{b\to\infty}\left(\frac{b+e^{2b}}{a+e^{4b}}\right)$

$19-\left(-7\right)$

$\int\left(-3x^2-2+\frac{9}{x}\right)dx$