From the first equation
6x - y = 1
6x - y - 1 = 0
6x - 1 = y
Substituting we get
4x - 3(6x - 1) = -11
|____|____|____|____|____|____|____|____|
0 1/16 2/16 3/16 4/16 5/16 6/16 7/16 8/16
| _________________| _________________|
0 1/4 2/4
1/10 is the answer if you divide 10,000 from 1,000