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[tex] \frac{6}{ \sqrt{7} - \sqrt{5} } \times \frac{ \sqrt{7} + \sqrt{5} }{ \sqrt{7} +\sqrt{5} } \\ = \frac{6( \sqrt{7} + \sqrt{5} )}{7 - 5} \\ = \frac{6( \sqrt{7} + \sqrt{5}) }{2} \\ [/tex]
2 dicoret dg 6

sisanya
[tex]3( \sqrt{7} +\sqrt{5} ) \\ = 3 \sqrt{7} + 3 \sqrt{5} [/tex]

jawabannya C