$\left(x-5x^2\right)\left(\frac{1}{2x\frac{1}{2}}\right)$

$\left(20x-1\right)+\left(20x+15\right)$

$\frac{x^2+x+6}{x^2+4}$

$4x^3-28x^2-x+7$

$\frac{sin}{x\sin\left(x\right)^2\cdot\cos\left(x\right)^2}$

$\int_0^4-\sqrt{16-\left(x-4\right)^2}dx$

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