$3x^2-36=0$

$2\sin\left(x\right)+2$

$\left(a^4+16\right)\left(a^2+4\right)\left(a+2\right)\left(a-2\right)$

$4x+9y+\left(-9y\right)+\left(-9x\right)$

$\lim_{x\to8}\left(\frac{2x-16}{6x^2-385}\right)$

$\lim_{x\to0}\left(\frac{tan\left(-3x\right)}{2^{5x}-1}\right)$

$\left(a+b-2c\right)\left(a-b+2c\right)$