z   x1    x2   x3   x4   s1   s2   s3 | RHS | Basic Variables| Ratio |
--------------------------------------|-----|----------------|-------|
1  -10    57    9   24    0    0    0 |  0  |        z       |       |
0  1/2 -11/2 -5/2    9    1    0    0 |  0  |       s1       |       |
0  1/2  -3/2 -1/2    1    0    1    0 |  0  |       s2       |       |
0    1     0    0    0    0    0    1 |  1  |       s3       |       |
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