Evaluate : `(sqrt(11)-sqrt(7))/(sqrt(11)+sqrt(7))`

Which of the following is the value of (sqrt(11)-sqrt(7)) (sqrt(11) + sqrt( 7)) ?

If a and b are rational numbers and (sqrt(11)-sqrt(7))/(sqrt(11) +sqrt(7))=a - b sqrt(77) . find the value of a and b.

In each of the following determine rational number a and b:(sqrt(11)-sqrt(7))/(sqrt(11)+sqrt(7))=a-b sqrt(77) (ii) (4+3sqrt(5))/(4-3sqrt(5))=a+b sqrt(5)

Evaluate (sqrt(7)-sqrt(5))/ (sqrt(7)-sqrt(5))

Evaluate (sqrt(5)-sqrt(3))/(sqrt(2)+sqrt(7))

Simplify the following expressions.(i) (5+sqrt(7))(2+sqrt(5)) (ii) (5+sqrt(5))(5-sqrt(5)) (iv) (sqrt(11)-sqrt(7))(sqrt(11)+sqrt(7))

Evaluate : (sqrt(7)+sqrt(5))/(sqrt(7)+sqrt(20)+sqrt(28)-sqrt(5)-sqrt(80))

Evaluate (sqrt(7)-sqrt(2))(sqrt(5)+sqrt(2))

Evaluate : ( sqrt(7) + sqrt(5) ) ( sqrt(5) - sqrt(7) )

Evaluate : ( sqrt(5) + sqrt(7 ) ) /( sqrt(5) - sqrt(7 ) )