$\left(n+12\right)\left(n-12\right)$

$\int\frac{7x^4}{3x^5+11}dx$

$\int\frac{x^{2}+53x+90}{\left(x^{2}+9\right)\left(x+7\right)}dx$

$x=3\sqrt{y-8}$

$\sin\left(\frac{y}{2}\right)\frac{dy}{dx}=\cos\left(3x\right)$

$\frac{7-x}{\left(x-2\right)\left(x+2\right)}=0$

$\int\left(sec^2\left(2t\right)\right)dt$