3x+7z+y=6.3 4x+10z+y=8.4 二元一次方程的解

若3x+7y+z=5,4x+10y+z=3,则x+y+z=? 已知3x+7y+z=315和4x+10y+z=420,求x+y+z 解方程组：3x+7y+z=31.5,4x+10y+z=42求 x+y+z 谢了3x+7y+z=315 4x+10y+z=4203x+7y+z=3154x+10y+z=420 已知x、y、z满足{3x+7y+z=5 ,求x+y+z的值 {4x+10y+z=3 已知x,y,z满足3x+7y+z=5 4x+10y+z=3 求x+y+z的值 已知4x-3y-6z=0,x+2y-7z=0,求5x+2y-z/2x-3y-10z 已知,方程组:4x-3y-7z=0 x+2y=10z 则(x-y+z)÷(x+y+z)=—— 2x+z=10 x+y-z=4 3x-y-z=0 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 已知3x+7y+z=6.3,4x+10y+z=8.4,那么x+y+z的值为? x-4y+z=-302x+y-z=18x--y-z=7 (4x+10y+z)-(3x+7y+z)=1.05, x+y/2=z+x/3=y+z/4 x+y+z=27 x+2y=3x+2z=4y+z 求x:y:z {2x+y=10 {x-y+z=4 {3x-y-z=0