Question

5/2√7-√5 rationalised the denominated​

Answer 1

$= \frac{5}{2 \sqrt{7} - \sqrt{5} } \\ = \frac{5}{2 \sqrt{7} - \sqrt{5} } \times \frac{2 \sqrt{7} + \sqrt{5} }{2 \sqrt{7} + \sqrt{5} } \\ = \frac{10 \sqrt{7} + 5 \sqrt{5} }{( {2 \sqrt{7} })^{2} - ( { \sqrt{5} })^{2} } \\ = \frac{10 \sqrt{7} + 5 \sqrt{5} }{28 - 5} \\ = \frac{10 \sqrt{7} + 5 \sqrt{5} }{23}$