知3x+7y+z=315,4x+10y+z=420,求x+y+z=?
知3x+7y+z=315,4x+10y+z=420,求x+y+z=?
已知3x+7y+z=315和4x+10y+z=420,求x+y+z
已知3X+7Y+Z=6 4X+10Y+z=7 求X+Y+Z=?
4X+Y+10Z=169 3X+Y+7Z=126 求X,Y,Z
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
谢了3x+7y+z=315 4x+10y+z=420
(x+y-z)(x-y+z)=
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
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
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