When there are fewer equations than unknowns there
are infinitely many solutions.  It is a dependent
system.  Here are some solutions:

x=-22, y=-11, z=46
x=-19, y=-9, z=41
x=-16, y=-7, z=36
x=-13, y=-5, z=31
x=-10, y=-3, z=26
x=-7, y=-1, z=21
x=-4, y=1, z=16
x=-1, y=3, z=11
x=2, y=5, z=6
x=5, y=7, z=1
x=8, y=9, z=-4
x=11, y=11, z=-9
x=14, y=13, z=-14
x=17, y=15, z=-19
x=20, y=17, z=-24
x=23, y=19, z=-29
x=26, y=21, z=-34
x=29, y=23, z=-39
x=32, y=25, z=-44
x=35, y=27, z=-49

You can set up this matrix:



and solve for a solution in terms of a letter,
but there is not just one solution.

Edwin