$\lim_{x\to\infty}\ln\left(2x+7\right)-\ln\left(x+1\right)$

$\sqrt{0}+5$

$\left(\frac{1}{3}xy-\frac{5}{2}x^3\right)^2$

$8x^3-12x^2y+16xy^2-x^3$

$\frac{dy}{dt}=\frac{2y\left(1-y\right)}{5}$

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

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