Question

X+2y-z=9
3x-2y+z=-1
2x-y-z=2

Answer 1

X+2y-z = 9 
3x-2y+z = -1  <<=== di tambah (+)
4x=8
x=2 <<== dapet x

2x-y-z = 2
3x-2y+z = -1 <<=== di tambah (+)
5x-3y=1
5.(2)-3y=1  <<=== masukan x yg tadi didapat
10-3y=1
3y=9
y=3 <<=== dapet y

2x-y-z = 2 <<=== masukan x dan y yg tadi di dapat
2.(2)-(3)-z = 2
4-3-z = 2
z = 1-2
z = -1 <<=== dapet z

jadi kita dapatkan x=2, y=3,dan z= -1

Answer 2

x+2y-z = 9 
3x-2y+z = -1
4x=8
x=2

2x-y-z = 2
3x-2y+z = -1
5x-3y=1
5.(2)-3y=1
10-3y=1
3y=9
y=3

2x-y-z = 2
2.(2)-(3)-z = 2
4-3-z = 2
z = 1-2
z = -1 <<=== dapet z