来自冯璞乔的问题
解2X+Y+3Z=13X-2Y+2Z=2-4X+4Y-Z=-1
解2X+Y+3Z=13X-2Y+2Z=2-4X+4Y-Z=-1
1回答
2020-09-01 17:16
解2X+Y+3Z=13X-2Y+2Z=2-4X+4Y-Z=-1
解2X+Y+3Z=13X-2Y+2Z=2-4X+4Y-Z=-1
2X+Y+3Z=1(1)
3X-2Y+2Z=2(2)
-4X+4Y-Z=-1(3)
(1)*2+(2)得
7X+8Z=4(4)
(2)*2+(3)得
2X+3Z=3(5)
(4)*2-(5)*7得
Z=2.6
代入(5)得
X=-2.4
代入(1)得
Y=-2