Write the simplest rationalising factor of   
         (i)          (ii)       (iii)         (iv)        (v)

(i) 2 x = 2 x = 4
     .^.. is the simplest rationalising factor of 2
(ii) x = = = 10
       .^..    is the simplest rationalising factor of
(iii) = ==
        x = = 5x3 = 15
         .^.. is the simplest rationalising factor of 
(iv) x = =
                        = 2x5=10
        .^.. is the simplest rationalising factor of  
(v) =
       Now x == 6
       .^..is the simplest rationalising factor of .