$\int\frac{40}{x^2+25}dx$

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

$\frac{\frac{1}{6}x^2+\frac{5}{36}xy-\frac{1}{6}y^2}{\frac{1}{3}x+\frac{1}{2}y}$

$-2x-\left(-\frac{3}{4}\right)\ge7\cdot\left(\frac{1}{4}x-\frac{1}{7}\right)$

$\lim_{x\to2}\left(\frac{3}{4}x-\frac{1}{2}\right)$

$\log\left(10x^4y\right)$

$12x^2y-18xy^2$