$\sqrt[5]{\left(m+n\right)^{10}}$

$\left(12x^3+6y^2\right)^2$

$\frac{x^2+5x}{-x^2-3x+3}$

$2^{-9}\cdot2^{18}$

$\lim_{x\to\infty}\left(\frac{\left(9x-2\right)^2}{x^3-8}\right)$

$3-2x=-x^2$

$\frac{2}{5}x+\frac{1}{3}y^{2}+\frac{1}{2}x-\frac{1}{6}y^{2}-\frac{4}{10}x+\frac{5}{2}y^{2}$