3x+2y-z=1,2x-y+2z=5,5x-2y+3z=13
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3x+2y-z=1,2x-y+2z=5,5x-2y+3z=13
![3x+2y-z=1,2x-y+2z=5,5x-2y+3z=13](/uploads/image/z/4472333-53-3.jpg?t=3x%2B2y-z%3D1%2C2x-y%2B2z%3D5%2C5x-2y%2B3z%3D13)
3x+2y-z=1 ①
2x-y+2z=5 ②
5x-2y+3z=13 ③
由③+①得:
8x+2z=14
即4x+z=7 ④
由①+②×2得:
7x+3z=11 ⑤
由④×3-⑤得:
5x=10
x=2
把x=2代入④得:
8+z=7
z=-1
把x=2,z=-1代入②得:
4-y-2=5
y=-3
所以方程组的解为:x=2 y=-3 z=-1
2x-y+2z=5 ②
5x-2y+3z=13 ③
由③+①得:
8x+2z=14
即4x+z=7 ④
由①+②×2得:
7x+3z=11 ⑤
由④×3-⑤得:
5x=10
x=2
把x=2代入④得:
8+z=7
z=-1
把x=2,z=-1代入②得:
4-y-2=5
y=-3
所以方程组的解为:x=2 y=-3 z=-1
x/2=y/3=z/5 x+3y-z/x-3y+z
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
x+y+z=2 x-3y+2z=1 2x+2y+z+5 要具体步骤..
3x+2y+z=14 ,x+y+z=10,z+2x+3y=1 5
x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
{5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=-
1,{2x+y+z=-26,x+2y+z=-30,x+y+2z=-28 2,{5x+2y+z=12,4x+3y+z=13
解下列方程组(1)3x-y+z=3 2x+y-3z=11 x+y+z=12(2)5x-4y+4z=13 2x+7y-3z
已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z.
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai