$\lim_{x\to\infty}\left(\sqrt{x^2+2x}-\sqrt{x^2+x}\right)$

$\left(7x^6y^4\right)^2$

$\frac{dy}{dx}=\frac{\left(1+5y\right)}{1+x}$

$\left(64f^6g^{-3}\right)^{\frac{1}{1}}\:x\:\left(81f^{-4}g^8\right)^{\frac{1}{2}}$

$\lim_{x\to0}\left(\frac{\tan\left(2x\right)}{\tan\left(5x\right)}\right)$

$9x^2+7y=6$

$169-b^2$