$\frac{x^3+3x^2+12}{x+4}$

$\sqrt{27u^{19}}$

$\left(-2xy^2+9xy^3\right)\left(2xy^2-9xy^3\right)$

$\frac{1}{6}x^{10}+\frac{7}{2}x^5+49$

$\lim_{t\to0}\left(\frac{1-\sin\left(x\right)}{1+\cos\left(x\right)}\right)$

$1-2a+2a^2$

$\left(\sec\left(a\right)+\tan\left(a\right)\right)\left(\sec\left(a\right)-\tan\left(a\right)\right)=1$