Question

rationalize the denominator
3÷(root5-root7)

Answer 1

$\frac{3}{\sqrt{5}-\sqrt{7} } \\\\= \frac{3 ( \sqrt{5}+\sqrt{7} ) }{\sqrt{5}-\sqrt{7} ( \sqrt{5}+\sqrt{7} ) } \\\\\\= \frac{3\sqrt{5} + 3\sqrt{7} }{5-7} \\\\= \frac{3\sqrt{5} + 3\sqrt{7} }{-2} \\\\\\= \frac{-3\sqrt{5} - 3\sqrt{7} }{2}$