Jon bought 1 2⁄3 pounds of green peppers and 3⁄5 pound of yellow peppers. how much more did the green peppers weigh than the yellow peppers?

Subtract 3/5 from 1 2/3.

Re-write the problem as "subtract 3/5 from 5/3."

 5     3
--- -
 3      5

Note that the LCD here is (3)(5) = 15.
Multiply 5/3 by (15/15) and also multiply 3/5 by (15/15).  Your result should be 

     25          9
     -  
      15        15

Subtracting, we get   16/15.  This is the answer.  The green peppers weighed 16/15 lb, or 1 1/15 lb, more than did the other peppers.

You didn’t put the necessary image to solve the question : p