5.｛7x+2y-z=7 ① 6.{9x+4y+z=10 ①

来源：学生作业帮编辑：神马作文网作业帮分类：数学作业时间：2024/11/13 13:17:33

5.｛7x+2y-z=7 ① 6.{9x+4y+z=10 ①
{6x-y+z=7 ② {-9x+2y+3z=-6 ②
{4x+3y+z=9 ③ {3x-4y+2z=5 ③
x=1,y=1,z=2 x=1,y=0,z=1

7x+2y-z=7 (1)
6x-y+z=7 (2)
4x+3y+z=9 (3)
(1)+(2)
13x+y=14 (4)
(1)+(3)
11x+5y=16 (5)
(4)×5-(5)
65x-11x=70-16
54x=54
x=1
y=14-13x=1
z=7x+2y-7=2
9x+4y+z=10 (1)
-9x+2y+3z=-6 (2)
3x-4y+2z=5 (3)
(1)+(2)
6y+4z=4
3y+2z=2 (4)
(2)+(3)×3
-10y+9z=9
10y-9z=-9 (5)
(1)×9-(2)×2
27y+20y=18-18
47y=0
y=0
z=(2-3y)/2=1
x=(5-2z+4y)/3=1

已知x/2=y/4=z/7,求①x：y：z.②若2x+y+3z=58,分别求x,y,z的值.③求x+y/x+z的值. 已知4x-3y-6z=0 ① ,x+2y-7z=0 ②,且x,y,z均不为0,求3x+2y+z÷x+2y+3z的值 2x+4y-3z=9① 3x-2y-4z=8② 5x-6y-5z=7③ 2x+4y+3z=9① 3x-2y+5z=11② 5x-6y+7z=13③ 已知,方程组:4x-3y-7z=0 x+2y=10z 则(x-y+z)÷(x+y+z)=—— 1.解下列方程组,①y-2z=1,x+3z=-1,3x-5y+z=21.②x+y+2z=7,x-2y-z=-4,2x+3 第1题 {x+2y+3z=4{y+z=1{3x+2z=3 第2题{x+y=7{y+z=10{z+x=9 第3题 {x+2 若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10 int x,y,z; x=2; y=4; z=7; x=y-- 解方程组：3X+4z=7①,2x+3y+z=9② ,5X-9y+7z=8③,,紧急 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X 解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y