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

$27^2$

$tan\left(x\right)-cos^2\left(x\right)=sin^2\left(x\right)$

$\lim_{x\to\infty}\left(1+\frac{9}{n}\right)^n$

$\left(-3x^3+2y^2\right)+\left(-8x^2+9xy\right)-\left(-3x^2-7\right)$

$\left(3y^{-1}\right)^{-1}$

$-2x\left(x^4-3x^2+5x-1\right)$