求x:y:z x:y=7/5:7/3,y:x=7:8
求x:y:z x:y=7/5:7/3,y:x=7:8
已知5x=3y,4z=7y,求x:y:z
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
X-Y-Z=4 3Y-X-Z=8 7Z--X-Y=16 这三个方程联立求x y z
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
已知x,y,z满足3x+7y+z=5 4x+10y+z=3 求x+y+z的值
已知x、y、z满足{3x+7y+z=5 ,求x+y+z的值 {4x+10y+z=3
求下列各连比已知x:y=3:7,y:z=7:5,求x:y:z已知x:y=4:7,y:z=2:5,求x:y:z已知x:y=
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
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X
5x+3y=25,2x+7y-3z=19,3x+2y-z=18,求x,y,z的值