$y'=\left(x+y+2\right)^2$

$\left(-7\:+\:21\right)\::\:\left(-1\:-1\right)$

$f\left(x\right)=\left(1+\frac{1}{x}\right)^x$

$-5-\left(1+\left(-7\right)\right)$

$2x+6y-2z^2+4x^3-2y+z^2$

$\left(3x+\sqrt{2}y\:+z\right)^2$

$\left(\frac{8}{3}x^2-\frac{7}{4}x^3+\frac{1}{2}x-6\right)-\left(\frac{1}{3}x^4+\frac{1}{2}x^3-x+\frac{7}{2}\right)$