$\lim_{x\to\infty}\left(\frac{2x^4+x^2}{x^4+\sqrt{x}}\right)$

$\frac{dy}{dx}=e\left(x+y\right)$

$\left(8^5\right)^4$

$c=\left(\senx+2\cos x\right)^{2}+\left(2\senx-\cos x\right)^{2}$

$\lim_{x\to0}\left(\frac{12\sin\left(x\right)-12x}{x^3}\right)$

$x^2+\frac{-1}{x^2}+1$

$\lim_{x\to-3}\left(x^2+x-6\right)$