$\left(2\:-\:x\right)\:\cdot\:\left(2\:+\:x\right)\:+\:\left(2x\:-\:1\right)\:\cdot\:\left(3x^2-\:2\right)$

$5-\left(7-2-3\left(3-9\right)\right)-3+4+12$

$\frac{d}{dx}x^3-3xy+y^3=1$

$\left(5x+2y\right)^3$

$\int e^x\left(3x^2+2x\right)dx$

$4\left(\infty^2\right)+1$

$\frac{\tan\left(a+b\right)-\tan b}{1+\tan\left(a+b\right)\tan b}=\tan a$