$-20-\left(-8+4-5\right)$

$\int\left(\frac{-4x}{x^2+2}\right)dx$

$\int\frac{x+2}{\left(x^4-x^2\right)}dx$

$\frac{dy}{dx}=\frac{2x^2-1}{y}$

$-3x>7$

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

$609.129+1023.5+67.890+55.50+789.45$