$\int\frac{2e^{-5x}}{e^{-5x}-9}dx$

$7m^2n-8m^3-6m^2n+3m^3$

$\left(x+y\right)^2+3x=15$

$( r ^ { 4 } ) ^ { 6 }$

$4\left(1+7x\right)-10\left(-9x+2\right)$

$\left(408.4\right)\left(2.2\right)+\frac{1}{2}\left(-110\right)\left(2.2\right)$

$x\left(512a^6+125k^2k^{16}\right)$