$2b+7b^2-2+3b-1+b$

$1x^4-7x^2-18$

$\int\:\:sen^2\left(\frac{x}{2}\right)cos^2\left(\frac{x}{2}\right)dx$

$\left(-35\right).\left(5+2\right)+\left(-4\right).9-\left(7-2.5\right)$

$\frac{x^2y^2-1}{xy+1}$

$\lim_{x\to0}\left(\frac{1-\cos\left(z\right)}{z^2}\right)$

$7\left(x+9\right)$