$asa$

$4-\left(6+5-12\right)\cdot\left(\left(4-7\right):\left(12-15\right)\right)$

$\frac{2x}{y}-\frac{x^2}{xy-y^2}+\frac{y}{x-y}$

$\int\left(x\left(2x-1\right)^5\right)dx$

$-2x+3y=20$

$\left(\frac{d^2r^3}{y^4}\right)^5$

$f\left(x\right)\:=\:\:2x\left(x\:+\:1\right)\left(x\:-\:4\right)^2\left(\:2x\:-\:3\right)$