$\lim_{x\to\infty}\left(\frac{x-1}{x^2+1}\right)^{x+1}$

$\frac{2}{5}=\frac{x}{10}$

$\int\cos\left(4x+5\right)dx$

$\frac{dy}{dx}=\left(x+1\right)t$

$\frac{dy}{dx}=10y^2-10$

$\left(5x\:-\:8y\right)\:\left(8y\:+\:5x\right)$

$\frac{\sin\left(x\right)^2-\tan\left(x\right)}{\cos\left(x\right)^2-\cot\left(x\right)}$