$\left(3x^5-5\right)\left(3x^5+5\right)$

$\left(\frac{2}{3x^{\frac{2}{3}}}\right)^2$

$\lim_{x\to-3}\left(\frac{x^2+12x}{x^2+4x+3}\right)$

$\frac{dx}{dy}=\:e^{x+2y}$

$\lim_{x\to0}\left(\frac{9^x-5^x}{9x}\right)$

$\frac{2x}{x-2}=\frac{x}{x-1}$

$y^2=\frac{9x^2-6}{x^2}$