解下列方程组:(1){x-y-z=6,y-x-z=0,z-x-y=-12} (2){2x+3y-z=41,x-y+2z=13,x-3y-4z=-1}

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解下列方程组:(1){x-y-z=6,y-x-z=0,z-x-y=-12} (2){2x+3y-z=41,x-y+2z=13,x-3y-4z=-1}
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解下列方程组:(1){x-y-z=6,y-x-z=0,z-x-y=-12} (2){2x+3y-z=41,x-y+2z=13,x-3y-4z=-1}
解下列方程组:(1){x-y-z=6,y-x-z=0,z-x-y=-12} (2){2x+3y-z=41,x-y+2z=13,x-3y-4z=-1}

解下列方程组:(1){x-y-z=6,y-x-z=0,z-x-y=-12} (2){2x+3y-z=41,x-y+2z=13,x-3y-4z=-1}
(1)x-y-z=6,(1)
y-x-z=0,(2)
z-x-y=-12 (3)
(1)+(2)得:
-2z=6,z=-3
(2)+(3)得
-2x=-12,x=6
(1)+(3)得
-2y=-6,y=3
所以,方程组的解是:
x=6
y=3
z=-3
(2)2x+3y-z=41 (1)
,x-y+2z=13,(2)
x-3y-4z=-1 (3)
(1)+(2)×3得
5x+5z=80 (4)
(1)+(3)得
3x-5z=40 (5)
(4)+(5)得:8x=120,x=15
代入(4)解得:z=1
把x和z的值代入(2)解得:y=4
所以,方程组的解是:
x=15
y=4
z=1