Question

तू प्लस सोचकर 5 - 2 _5​

Answer 1

2+√5/2-√5

=(2+√5)(2+√5)/(2-√5)(2+√5)

=(2+√5)^2/(2)^2-(√5)^2

=(2)^2+2*2*√5+(√5)^2/4-5

=4+4√5+5/-1

=9+4√5/-1

=-(9+4√5) (This is the required answer.) [If you liked my answer then please mark me as brainliest and I will definitely follow you back.]

Answer 2

Answer:

-(9+4√5)

Step-by-step explanation:

given expression is ;

$\frac{2 + \sqrt{5} }{2 - \sqrt{5} }$

By rationalising the denominator

$\frac{2 + \sqrt{5} }{2 - \sqrt{5} } \times \frac{2 + \sqrt{5} }{2 + \sqrt{5} }$

$\frac{( {2 + \sqrt{5} })^{2} }{ {2}^{2} - { \sqrt{5} }^{2} }$

as (a+b)(a-b)=a2-b2

and (a+b)^2=a^2+2ab+b^2

$\frac{ {2}^{2} + 2 \times 2 \times \sqrt{5} + { \sqrt{5} }^{2} }{4 - 5}$

$\frac{4 + 4 \sqrt{5} + 5 }{ - 1}$

$- (9 + 4 \sqrt{5})$