$\left(\frac{-50a^3b^9}{75a^7b^{10}}\right)$

$\left(2x\right)^3\:+3.\:2x^2\:.\:8\:+\:3.\:2x\:.8^2\:+\:8$

$\cot\:\left(\frac{\pi\:}{2}-\theta\:\right)\cos\left(\theta\right)$

$5x^2-7x^2+3x^2-2x^2$

$+24-5-9+3+2$

$\left(x+2\right)^2+12\left(x+2\right)+27$

$\to\frac{1}{6x^{-\frac{3}{2}}}$