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

$x^2+64=-20x$

$\frac{d}{dx}\left(y^3+7xy+4x^3-7x=0\right)$

$\int_{0}^{\infty}\frac{1}{2x-1}dx$

$\lim_{x\to\infty}\left(\frac{x+\sin^2\left(x\right)}{x+\cos\left(x\right)}\right)$

$\frac{cot\left(x\right)+tan\left(x\right)}{csc^2\left(x\right)}tan\left(x\right)$

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