4X – Y +2z = 15, 3Y -Z = 2 jika X=6, maka ……………..

4x-y+2z=15
4.6 -y+2z =15
24-y+2z=15
-y+2z =-9
2z +9 =y …. persamaan 1
3y-z=2 ….. persamaan 2
3(2z+9)-z =2
6z+27-z=2
5z=-25
z=-5
y=-1