$\frac{-a^3b^4}{6a^3b^2}$

$\int\frac{x^2+e^x}{\left(x^3+3e^x+ln\:2\right)^2}dx$

$\frac{9x^3+15x^2+5x+14}{3x^2+4}$

$\frac{x^2}{\left(1-x^3\right)^2}$

$\arctan\left(\frac{\frac{1}{2}}{\frac{\sqrt{3}}{2}}\right)$

$\frac{x^2-6x+6}{x-3}$

$\left(7+3\right)-\left(5+4\right)$