$\int\:\frac{7x+1}{\left(x+3\right)\left(x+1\right)}dx$

$\lim_{x\to\infty}\left(\frac{9}{x}-sin\left(\frac{9}{x}\right)\right)\cdot x^3$

$-5r+5r$

$\frac{1x^3+1x^2+1x^1+1}{x^2-2}$

$\frac{dy}{dx}=e^{6x}\cos\left(3x\right)$

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

$1x^3+7^2-x+28$