If `P + sqrt3 Q + sqrt5 R + sqrt15 S= 1/(1+sqrt3 + sqrt5)` then the value of P is

If p + q = sqrt13 p - q = sqrt5 then the value of pq is ____

If p + q = sqrt13 and p -q = sqrt5 , then the value of pq is

If x= ( sqrt5- sqrt3)/ ( sqrt5+ sqrt3) and y= ( sqrt5+ sqrt3)/( sqrt5- sqrt3) find the value of x^(2) + y ^(2)

If 2sqrtx= (sqrt5 + sqrt3)/(sqrt5 - sqrt3)-(sqrt5 - sqrt3)/(sqrt5 + sqrt3) then what is the value of x ?

If p + sqrt q = r + sqrts , then