$x^2-6x+12$

$\int2e^{2x}\cdot\left(e^{2x}+4\right)^5$

$\sqrt{\left(5+2\sqrt{6}\right)\left(5-2\sqrt{6}\right)}$

$3\left(5x^2-3x+2\right)-4\left(2x^2-5x+2\right)$

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

$\int\frac{x^2+19x\:+\:36}{x^3+\:7x^2+12x}dx$

$\frac{1}{\sin\left(a\right)\cdot\cos\left(a\right)}=\sec\left(x\right)$