$\frac{d^n}{dx^n}\left(x+7x^{\frac{1}{3}}+x^{\frac{2}{3}}\right)$

$\frac{2x^{a+4}}{-x^{a+2}}$

$\frac{\cos\left(x\right)\cdot sec\left(x\right)}{1+\tan^2\left(x\right)}=cos\left(x\right)$

$\lim_{x\to0}\left(\frac{x^2sec^2\left(x\right)-x^2}{x^2\left(x^2sec^2\left(x\right)\right)}\right)$

$x\frac{4}{3}x-3$

$16x^2-36=0$

$16x^4-56x^2y^2+49y^4$