$\frac{d}{dx}\left(xe^{-y}+y^2=1\right)$

$\lim_{x\to-\infty}\left(3tan5x\right)$

$\frac{\sin^2\left(x\right).\left(\cot\left(x\right)-\csc\left(x\right)\right)}{\cot\left(x\right)+\csc\left(x\right)}$

$\left(2y+7x\right)^2$

$36y^2-27-8y^2-54y$

$\left(a^2+a^5\right)^2$

$8\left(x^2-3x\right)$