$0.7x^2-\frac{1}{3}xy^2+x^2-3x^2+\frac{1}{6}xy^2$

$2+x-x^2$

$\frac{1-sen\left(x\right)}{\cos\left(x\right)}=cos\:\left(x\right)$

$\left(2+b\right)^5$

$\lim_{x\to\infty}\left(\frac{10x^2}{e^{\left(7x\right)}}\right)$

$2\sqrt{2}-2\sqrt{2}$

$\left(3x^2+6xy-5y^2\right)\left(x+3y\right)$