$4x^2y-12x^2y^2+9xy^3$

$9+2\left(-8x-15\right)=-10x-3-12x$

$\left(x+3\right)\left(x-3\right)\left(x-2\right)\left(x+2\right)+13x^2-36$

$\frac{8x^3}{2x^9}$

$-15x^3y^4z^2-3xz^5\:$

$\frac{\tan\left(89\right)-\tan\left(1\right)}{\tan\left(88\right)}$

$\sqrt{100x^5y^{11}}$