$\int\frac{\left(x^2-2x-3\right)}{\left(x^2+1\right)\left(x+1\right)}dx$

$-15+\left(-15\right)-\left(-6\right)$

$4m+5m+7m-m$

$2x^2+x+4=0$

$\lim_{x\to0}\left(a\right)$

$2\cot^2\left(x\right)=\frac{1}{\sec\left(x\right)-1}-\frac{1}{\sec\left(x\right)+1}$

$3a^3-4a^2-405a-650$