$\left(\sec\left(x\right)-\cos\left(x\right)\right)x\left(\csc\left(x\right)-\sin\left(x\right)\right)$

$\left(5y+2x\right)\left(5y+5\right)$

$\lim_{x\to\infty}\left(x^9sin\left(\frac{2.5}{x^9}\right)\right)$

$6-\frac{1}{2}\cdot12$

$\left(2z-3xy\right)^2$

$x=y^2-2$

$1^{-\frac{1}{4}}$