$\lim_{x\to1}\frac{\sqrt{x^2-3x-1}-\sqrt{x^3-3x-1}}{x-1}$

$-y+7y$

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

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

$\lim_{x\to0}\left(\frac{1-\cos\left(\left(2x\right)\right)}{x^2}\right)$

$\cos\:\left(x\right)-4\cos\:\left(x\right)\sin\:^2\left(x\right)$

$2^{16}\cdot3^4\cdot5^4$