解下列方程组(1){x+y-z=-3,2x+y-3z=-2,3x-y+2z=-11(2){5x-4y=0,3y-5z=0,2x-y+z=6

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解下列方程组(1){x+y-z=-3,2x+y-3z=-2,3x-y+2z=-11(2){5x-4y=0,3y-5z=0,2x-y+z=6解下列方程组(1){x+y-z=-3,2x+y-3z=-2,3

解下列方程组(1){x+y-z=-3,2x+y-3z=-2,3x-y+2z=-11(2){5x-4y=0,3y-5z=0,2x-y+z=6
解下列方程组(1){x+y-z=-3,2x+y-3z=-2,3x-y+2z=-11
(2){5x-4y=0,3y-5z=0,2x-y+z=6

解下列方程组(1){x+y-z=-3,2x+y-3z=-2,3x-y+2z=-11(2){5x-4y=0,3y-5z=0,2x-y+z=6
1)
x+y-z=-3 ①
2x+y-3z=-2 ②
3x-y+2z=-11 ③
②+③得:5x-z=-13
z=5x+13 ④
②-①得:x-2z=1 ⑤
④代入⑤得:x-10x-26=1
x=-3
z=5x+13=-2
将x=-3,z=-2代入①得:-3+y+2=-3
y=-2
所以,原方程组的解为:x=-3,y=-2,z=-2
2)
5x-4y=0 ①
3y-5z=0 ②
2x-y+z=6 ③
由③得:z=6+y-2x ④
将④代入②得:3y-30-5y+10x=0
5x-y=15 ⑤
⑤-①得:3y=15
y=5
将y=5代入①得:5x-20=0
x=4
将y=5代入②得:15-5z=0
z=3
所以原方程组的解为:x=4,y=5,z=3

{x-2z=1,4x+z=-14
9x=-27
x=-3
z=-2
y=-2

{x=4y/5,z=3y/5,2x-y+z=6
2*4y/5-y+3y/5=6
8y-5y+3y=30
y=5
x=4
z=3