$l=\left(x+4\right)\left(x+2\right)+\left(x+3\right)\left(x+5\right)-2x\left(x+7\right)+7$

$n-2n+2n+12$

$=vw+cv_{c}w$

$\left(a+6b^2\right)\left(a-4b+2x\right)$

$\int_{-\infty}^0\left(\frac{15}{\left(x-1\right)^2}\right)dx$

$\left(2m+w\right)^2$

$\frac{1}{5}\arctan\left(\frac{y}{5}\right)+c=x+c$