$\frac{x^2+2x}{x^2-4}$

$\sqrt{2-\sqrt{3}}\cdot\sqrt{2+\sqrt{3}}$

$\left(-5\right)\left(+2\right)\left(0\right)\left(4\right)$

$\frac{1}{\sec^2\left(x\right)+\csc^2\left(x\right)}$

$\left(6n-33a\right)^2$

$\left(2a\:-\:3\right)^2$

$\int_0^{\frac{1}{\sqrt{10}}}\left(\frac{x}{\sqrt{1-25x^4}}\right)dx$