Answer :
8- | a b
7- |
6- |
5- |
4- |
3- |
2- | x c
1- |______________________________
0 1 2 3 4 5 6 7 8 9
x,x=1,2
7- |
6- |
5- |
4- |
3- |
2- | x c
1- |______________________________
0 1 2 3 4 5 6 7 8 9
x,x=1,2