$x^2+y^2-\left(x^2+2xy+y^2\right)+\left[-x^2+y^2\right]$

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

$\left(x+1\right)^2-\left(x-2\right)^2-\left(x+3\right)^2+\left(x+4\right)^2$

$\left(y^2+1\right)\left(y^2-3\right)$

$6x^2+43x-40$

$\left(-3.7\right)+\left(-2.9\right)$

$\int_0^{\frac{\sqrt{2}}{2}}\left(\frac{t^2}{\left(1-t^2\right)^{\frac{3}{2}}}\right)dx$