According to the first formula 3x+z=23.

By the second formula x+y-y/y=9

By the third formula z+yz=24

This equation group has two sets of solutions.

x= 12，y=-2，z=- 13

Or x=6, y=4 and z=5.

Then x+y+z = -3 or x+y+z = 15.