Question

please explain
if (√7+√5)/(√7-√5) - (√7-√5)/(√7+√5) = a+√35b find value of a and b

Answer 1

={(√7+√5)(√7+√5)-(√7-√5)(√7-√5)/
(√7-√5)(√7+√5)
We know that
(a-b)(a+b)=a^2 -b^2
={(√7+√5)^2 -(√7-√5)^2}/(√7)^2 -(√5)^2
{(√7+√5-√7+√5)(√7+√5+√7-√5)}/7-5
=(2√5)(2√7)/2
=[4√35]/2=2×√35=2×5.91=11.82

Answer 2

here is your answer, hope it helps you.