$100a^2b^3c-150b^2+50ab^3c^3-200bc^2$

$\left(+9\right)-\left(+6\right)-\left(-2\right)-\left(+8\right)$

$\cos\left(\frac{2\pi}{5}\right)\cdot\cos\left(\frac{\pi}{5}\right)$

$2^2-8x+16$

$\left(x-3\right)\frac{dy}{dx}+3y=x\left(x-3\right)$

$x^2y'+2xy\:=3x^2\:$

$x-3y=3$