Question 520733
2/6 - 2/3=???
  
  2/6-2/3=  2/6 - 2/3(2/2)                  
         =  2/6 - 4/6
         =  -2/6
         = -1/3

or we can do like this

2/6-2/3 =  (2*1)/(2*3) - 2/3
        =  1/3 - 2/3
        =   -1/3