$-x^3+x^2+6x$

$7^2-2^2$

$\left(2\right)\left(\frac{1}{4}\right)\left(16\right)$

$-xy^2+y\frac{dx}{dy}+x=0$

$\frac{dy}{dx}\left(y=x\sqrt{\frac{x^2-9}{x^2+9}}\right)$

$1-\left|7-\left(8+12-3\right)-7\right|-35+\left(4+18-15\right)$

$\lim_{x\to-3}\left(\frac{x^2+x-6}{x^2+4x-3}\right)$