$n^2-9n-20$

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

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

$\int\sqrt{4x+8}.dx$

$2 y ^ { 2 } + 6 y ^ { \prime } - 176 y = 0$

$\int\frac{1}{\left(9x^2-441\right)^{\frac{3}{2}}}dx$