x-y+z=5 (1)
2x+3y+z=-2 ( 2)
x-2y-z=3(3)
由（1）得 z =5+y- x(4)
把(4)代入( 2)中得 2x+3y+5+y- x=-2
x+4y+5=-2 (5)
把(4)代入( 3)中得x-2y-(5+y- x)=3
2x-3y-5=3 (6)
由（5）（6）得
x=1 y=-2
把x=1 y=-2代入（1）得
1-（-2）+z=5
z=2
∴x=1
y=-2
z=2
x-y+z=5 2x+3y+z=-2 x-2y-z=3
2个回答
相关问题
-
证明：（y+z-2x）3+（z+x-2y）3+（x+y-2z）3=3（y+z-2x）（z+x-2y）（x+y-2z）．
-
x+y+z=2 ① 2x+3y+z=38 ① x+y=3 3x-y-4z=5 ② 3x+4y+2z+56 ② y+z=5
-
x-5y-3z=0 y+z-3x=3 x+y+3z=14 y+4z=3 z+x-3y=5 2x+y+z=7 2x-z=1
-
x+2z=3 x+y+z=2 2x+y=2 3x-y-4z=5 2y+z=7 2x+3y-2z=0
-
(2X-3Y+Z)-3{X-2[-Z+(X-Y)]-(3Y-5Z)}
-
x:y=3:5,y:z=2:3求X+Y+Z/2X-Y+Z
-
x+y-z=0 2x-3y+2z=5 x+2y-z=3
-
x+y-2z=0 3x-2y-2z=-5 2x+y-z=3
-
x＾2(y+z)+y＾2（z+x）+z＾2(x+y）-(x＾3+y＾3+z＾3）-2xyz
-
｛5x — 3y+z=2｛5x+2y — 4z=3｛—5x+y — z=2