$\left(x^2-x\right)^2-\left(x^2-x\right)$

$\left(b^2-13b+10\right)+\left(-2b^2+5\right)$

$\tan\left(30\right)^2-\cot\left(30\right)^2$

$5x^{-4}y^2\frac{\left(2x^{-1}y^4\right)^{-2}}{4x^2y^{-3}}$

$\int\frac{\cos4x}{2+\sin4x}dx$

$24=2x+x^2$

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