$7rs+2rs+3rs$

$\left(2x\:-\:4\right)\left(3x\:-1\right)$

$1-\left(5-3+2\right)-\left|5-\left(6-3+1-2\right)\right|$

$\frac{10x^3+10x^220x^{-2}-28}{2x^{-2}}$

$\frac{dy}{dx}\left(x^2=\left(4x^2y^3+1\right)^2\right)$

$\lim_{x\to\infty}\left(\frac{x+c}{x-c}\right)$

$\sqrt{200x^7y^8}$