each letter above the line represents a digit that has a difference of one from the digit represented by the same letter below the line.
1)the digits are 0,1,2,3,4,5,6 and 7
.. F F B E D F
-.G C G F D A
_____________
......B E D A F
2) digits 0,1,2,3,4,5,6 and 7
..A G H C D B E
+D C F G C A F
_____________
E E F G E E C E
3) digits 0,1,2,3,4,5 and 6
..A A C B E F D
+D F E B C A A
_____________
..C E D D F A C
what digit or digits are represented by each letter?
(ignore periods plz)