$\frac{d^2z}{dx^2}\left(x^2y^2-y^3+3x^4+5\right)$

$\lim_{x,y\to0,0}\left(\frac{x^3}{2x^2+y^4}\right)$

$\frac{dy}{dt}=\frac{\left(-y+180\right)}{15}$

$x^6-6x^5+9x^4$

$\int25\cos25xdx$

$\left(-4\right)\cdot\left(+2\right)-\left(3\right)+\left(-5\right)-\left(-6\right)\cdot\left(-4\right)$

$2x^2-x=2$