$\displaystyle \sqrt{ \frac{16}{63} }$\displaystyle \sqrt{ \frac{16}{63} }

$\displaystyle \frac{16}{3\sqrt{7}}$\displaystyle \frac{16}{3\sqrt{7}}

$1$1

$\displaystyle \frac{3+\sqrt{7}}{3\sqrt{7}}$\displaystyle \frac{3+\sqrt{7}}{3\sqrt{7}}