$\left[+3\right]-\left[-19\right]$

$\:\left(2x.2x\right)+\left(2x+3.3\right)+\left(3.2x\right)$

$-25x=75$

$\lim_{x\to0}\left(\frac{\sin\left(6x\right)^2}{x^2}\right)$

$\frac{1}{4}a\:-\:5a\:+\:12a$

$\int\:\sqrt{8+2x-x^2}dx$

$\tan\left(x\right)\:\cot\left(x\right)\:-\:\sin^2\left(x\right)=\cos^2\left(x\right)$