can u tell me how 2 add a
fraction with the 
donominators r 
not the same

 A     C
--- + ---
 B     D

is equal to

 AD + BC
---------
   BD

then add AD and BC, then 
reduce the fraction to 
lowest terms

Example

 2     4
--- + ---
 3     5

is equal to

 (2)(5) + (3)(4)
----------------
      (3)(5)

   10 + 12
  ---------
      15

     22
   ----- or 1 7/15
     15

Example

 4     1
--- + ---
 9     6

is equal to

 (4)(6) + (9)(1)
----------------
      (9)(6)

   24 + 9
  ---------
     54

     33
    ----
     54
 
     11
    ----
     18

Edwin