Question 96720
  

  x= 5y; 1/x + 1/y= 1/5

  1/5y + 1/y = 1/5

    (1+5) /5y = 1/5

         6/5y = 1/5

         6*5 = 5y 

        30 = 5y

        6 = y

CHECK :

1/x + 1/y = 1/30 + 1/ 6
          = (1 + 5)/30 = 1/5