$\tan3x=0$

$\frac{x^3}{1-2x}$

$\left(2x\sqrt{x^2+1}\right)^2$

$\lim_{x\to+\infty}\left(\frac{\left(e^x-2\right)}{\left(x^2\right)}\right)$

$t^2y^2\frac{dy}{dt}=1$

$5\left(m-8\right)\left(m+15\right)$

$-4\cdot\left(6-\left(+4\right)\right)\:-\frac{\left(\left(-8\right)\:-\left(+16\right)\right)}{2}$