$-\frac{7}{\left(1+7x\right)^2}$

$\:\:v\:+\:61\:=\:92\:$

$\frac{sen^3u}{tan\:u\:-senu}=cos\:u\:\left[1+cos\:u\right]$

$\lim_{x\to\infty}\left(\frac{ln\left(x^6\right)}{x^7}\right)$

$0.4a-\frac{2}{5}a$

$-\frac{27}{8}n-\frac{3}{2}+\frac{29}{6}n$

$\int_1^2\left(\frac{4x^2-2x-12}{x\left(x+2\right)\left(x-3\right)}\right)dx$