Respuesta :

sthashreya1220
  1. 1/b-1/a = 1/c-1/b [ since they are in arithmetic progress]
  2. 1/b+1/b = 1/c+1/a
  3. 2/b = (a+c)/ac
  4. 2ac = b(a+c)
  5. 2ac/(a+c) =b