$x+9+2x-2x-3$

$\frac{dy}{dx}=x^4-2x^3+5x^2-2x$

$c^4-324$

$3x+7=x-9$

$\frac{dy}{dx}\left[y+cos\left(2x-y\right)=3\right]$

$\frac{1}{81}x^2\cdot\frac{1}{18}x\cdot\frac{1}{16}$

$\left(1+\sin\left(\infty\right)\right)\cdot\left(1-\sin\left(\infty\right)\right)=\cos\left(\infty\right)^2$