$m-2m$

$\int\frac{6x-7x^2}{\left(x+1\right)^2}dx$

$cotx+\frac{1}{cotx\:}=\frac{\left(\left(cotx\right)^2+1\right)}{\left(cotx\right)^2}$

$\frac{dx}{dy}=\frac{2y}{v}+\frac{1}{2}yv$

$\left(\sec\left(x\right)+\tan\left(x\right)\right)\left(\csc\left(x\right)-1\right)=\cot\left(x\right)$

$\frac{2x^2\left(x-3\right)}{5\left(x+3\right)}$

$2.3r-1.1r$