Question

rationalise the denominator of the following :

$\frac{4}{2 + \sqrt{3} + \sqrt{7} }$
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Answer 1

4:2+√7+√3

Hope I am correct....

Answer 2

Answer:

Multiply numerator & denominator by (5√+3√)(5+3)

=(5√+3√)2(5√−3√)(5√+3√)=(5+3)2(5−3)(5+3)

=5+215−−√+35−3=5+215+35−3

=8+215−−√2=8+2152

=4+15−−√=4+15

Formulae used:

(a+b)2=a2+2ab+b2(a+b)2=a2+2ab+b2

(a−b)2=a2−b2