$5x^2-x^2$

$\int\left(3x-2\right)tan\left(3x^2-4x+11\right)dx$

$\left(x+b+z\right)^2$

$\left(xy-mn\right)\left(xy+mn\right)$

$\frac{d}{dx}\left(9x^2+9y^2=\left(x^2+y^2-5x\right)^2\right)$

$\frac{\left(4x^2\:-\:1\right)}{x^2+\:3}$

$\left(\frac{\left(ab^2\right)\frac{1}{3}}{a^2\cdot\left(b^2\right)^2}\right)^2$