$\left(y\ln\left(x\right)\right)\frac{dy}{dx}=\left(\frac{x}{y+1}\right)^2$

$\left(b+20\right)^2$

$\lim_{x\to\infty}\left(\frac{5x+8}{5x+3}\right)^{7x}$

$\frac{72x^5}{-3x^2}$

$c-2=\frac{18}{c}+7$

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

$\sqrt{9-2}$