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

$sen\left(3t\right)\cdot sen\left(5t\right)$

$\frac{d}{dt}\left(i=\frac{1}{2}z^2+3z+2w^2-w+100\right)$

$\lim_{x\to2}\left(\frac{x+2}{\left(x-2\right)^2}\right)$

$\frac{15x^7+20x^2-10x^2}{5x^2}$

$14cos\:\left(x\right)\:+\:30\:=\:0\:$

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