1.3(x+y)-4(x-y)=4 x+y/2 + x-y/6 =6 2.x+2y+3z=7 2x+y+z=7 3x+y

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：2024/09/30 22:31:17

1.3(x+y)-4(x-y)=4 x+y/2 + x-y/6 =6 2.x+2y+3z=7 2x+y+z=7 3x+y+2z=11 3.x:y:z=1:2:7 2x-y+3z=21
4.4x-3y=1 x+2y-z=5 3x-y+2z=2

1:1.3(x+y)-4(x-y)=4,(1)
x+y/2 + x-y/6 =1 (2)
由(1),得:x=7y-4,代入(2),得
14y-y/3=9,y=27/41,x=25/41
2.5x+4y+z=0,(1)
3x+y-4z=11,(2)
x+y+z=-2 (3)
4(1)+(2):
23x+17y=11 (4)
(1)-(3):
4x+3y=2 (5)
3(4)-17(5):x=-1
由(5),y=2
由(3),z=-3

2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X 已知4x-3y-6y=0,x+2y-7z=0.求x-y+z\x+y+z的值 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z 已知有理数x、y、z满足条件|x-z-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x、y、z 4x-3y-6z=0,x+2y-7z=0是一个方程组,那么x-y+z/x+y+z的值等于若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, ①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z-