$\frac{x^5^4+x^2-2}{x^2+1}$

$\lim_{t\to0}\left(\frac{e^{5t}-1}{sin\left(t\right)}\right)$

$2xy^4+x^3y-4x^2y^2+3x^2y-2xy$

$\sqrt[3]{\frac{\left(1-x^2\right)}{\left(1+x^2\right)}}$

$\int7x\left(\sqrt{6x^2+3}\right)dx$

$-2\left(3+8r\right)+6r$

$\left(x+\sqrt{x}+1\right)\left(x+\sqrt{x}-1\right)-\left(x-1\right)^2$