Question

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please answer a and b

Answer 1

Hey Mate

your answer is ----


a ) we have ,

$\frac{4 + \sqrt{5} }{4 - \sqrt{5} } + \frac{4 - \sqrt{5} }{4 + \sqrt{5} } \\ \\ = \frac{ {(4 + \sqrt{5)} }^{2} + {(4 - \sqrt{5)} }^{2} }{ {4}^{2} - { \sqrt{5} }^{2} } \\ \\ = \frac{16+ 5 + 8 \sqrt{5} + 16 + 5 - 8 \sqrt{5} }{16 - 5} \\ \\ = \frac{42}{11}$



b ) we have ,

${(2 \sqrt{5} + 3 \sqrt{2)} }^{2} \\ \\ = 20 + 18 + 12 \sqrt{10} \\ \\ = 38 + 12 \sqrt{10}$



HOPE IT HELP YOU

Answer 2

hope this will help you