10X+5Y+Z=70 X+Y+Z=15

来源：学生作业帮编辑：搜搜考试网作业帮分类：数学作业时间：2024/05/04 18:56:21

10X+5Y+Z=70 X+Y+Z=15
10X+5Y+Z=70
X+Y+Z=15

两式相加10X+5Y+Z+X+Y+Z=70+15
11X+6Y+2Z=85
两式相减(10X+5Y+Z)-(X+Y+Z)=70-15
9X+4Y=65
所得两式相减(11X+6Y+2Z)-(9X+4Y)=85-65
2X+2Y=20
X+Y=10
代入X+Y+Z=15,所以Z=5
把Z=5代入10X+5Y+Z=70,得10X+5Y+5=70,10X+5Y=65
由X+Y=10, 得5X+5Y=50
10X+5Y=65,5X+5Y=50两式相减得5X=15,X=3
X+Y=10,Y=7
所以X=3,Y=7,Z=5

(x+y-z)(x-y+z)= X+Y+Z=? x/2=y/3=z/5 x+3y-z/x-3y+z 若{x+3y+10z=0 则 (x+y-z)/(x-y+z) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai x+y=10 y+z=15 z+x=20 求x,y,z等于多少? 解方程组x+y-z=-5,x-y-z=1,x-y+z=15 方程组x-y-z=5 y-x-z=1 z-x-y=-15的解是? 若x+3y+5z=10,5x+z+3y=8,x+y+z=? 若X+6Y+4Z=10 4X+4Y+Z=15求X+Y+Z {5X+Y+Z①X+5Y+Z=-2②X+Y+5Z=10③ {2x+3y-4z=-5 x+y+z=6 x-y+3z=10