4X-9Z=17 3X+Y+15Z=18 X+2Y+3Z=2

问题描述:

4X-9Z=17 3X+Y+15Z=18 X+2Y+3Z=2

4X-9Z=17 (1)
3X+Y+15Z=18 (2)
X+2Y+3Z=2 (3)
(2)*2-(3) 5x+27z=34 (4)
(1)*3+(4) 17x=85
x=5
代入(1)得 z=1/3
两者共代入(3)得 y=-2
综上:x=5,y=-2,z=1/3