[tex]3 \sqrt{7} \sqrt{7} = 3 \sqrt{ {7}^{2} } = 3 \times 7 = 21 \\ 6 \sqrt{ {7}^{5} } = 6 \sqrt{ {7}^{4} \times 7 } = 6 \times {7}^{2} \sqrt{7} = 294 \sqrt{7} \\ \frac{21}{294 \sqrt{7} } = \frac{1}{14 \sqrt{7} } \\ \\ or \: \frac{1}{14 \sqrt{7} } \times \frac{ \sqrt{7} }{ \sqrt{7} } = \frac{ \sqrt{7} }{14 \times 7} = \frac{ \sqrt{7} }{98} [/tex]
