Math, asked by lovi3, 1 year ago

7+3 root 5 / 3+root 5 - 7-3root5 /3-root5

Answers

Answered by skh2
47

Please refer to the above photo for the used process

Hope this will be helping you
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Answered by mysticd
29

Answer:

\frac{7+3\sqrt{5}}{3+\sqrt{5}}-\frac{7-3\sqrt{5}}{3-\sqrt{5}}= \sqrt{5}

Explanation:

Given \frac{7+3\sqrt{5}}{3+\sqrt{5}}-\frac{7-3\sqrt{5}}{3-\sqrt{5}}

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

= \frac{(21-7\sqrt{5}+9\sqrt{5}-15)-(21+7\sqrt{5}-9\sqrt{5}-15)}{3^{2}-\left(\sqrt{5}\right)^{2}}

= \frac{21-7\sqrt{5}+9\sqrt{5}-15-21-7\sqrt{5}+9\sqrt{5}+15}{9-5}

=\frac{(-14\sqrt{5}+18\sqrt{5})}{4}

= \frac{4\sqrt{5}}{4}

= \sqrt5

Therefore,

\frac{7+3\sqrt{5}}{3+\sqrt{5}}-\frac{7-3\sqrt{5}}{3-\sqrt{5}}= \sqrt{5}

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