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

$\frac{dh}{dt}=-\frac{1}{10}\sqrt{h}$

$32a^4b^5\sqrt[4]{ab^2}$

$\lim_{n\to\infty}\left(2+\frac{1}{n^2}\right)$

$\lim_{x\to-\infty}\left(\frac{e^x}{x^{-2}}\right)$

$\frac{dy}{dx}=x+4y,\:y\left(0\right)=6$

$8y+21\ge2y-54$