(1){y=2x-1,①
2x+3y+z=8,②
3x+2z=-4③
②×2-③,得
x+6y=20④
①代入④,得
x+12x-6=20
13x=26
x=2代入④,得
2+6y=20
y=3
所以
z=8-2x-3y=8-2×2-3×3=-5
即
x=2
y=3
z=-5
y=2x-1 (1)
2x+3y+z=8 (2)
3x+2z=-4 (3)
由(3)得z=-2 -(3/2)x
y=2x-1 z=2-(3/2)x代入(2)
2x+3(2x-1)+[2-(3/2)x]=8
整理,得
13x=9
x=9/13
y=2x-1=18/13-1=5/13
z=2- (3/2)x=2-(3/2)(9/13)=25/26
x=9/13 y=5/13 z=25/26