Find n, if the ratio of the fifth term from the beginning to the fifth term from the end in the expansion of  isÂ
Suppose that in the expansion of the term that containsÂ
 isÂ
Now, Â Â Â Â Â Â
     Power of x = 8 - r
  Power of x required = 5          8 - r = 5 or r = 3
∴    containsÂ
         Â
Hence, the co-efficient ofÂ
              Â
               Â