﹛3x+2y+2z=140 5x+3y+3z=220 则x=?y=?z=?

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/06 12:22:53

3x+2y+2m=140 ①
5x+3y+3m=220 ②
把①×3 ②×2 可得,
9x+6y+6m=420 ③
10x+6y+6m=440 ④
③-④ 得,x=20
把x=20带入①和②
得,
60+2y+2m=140
100+3y+3m=220
直接解得,y+m=40
∴x+y+m=40+20=60（m是Z)

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) x/2=y/3=z/5 x+3y-z/x-3y+z 若x/3=y/2=z/5,则2x-3y-z/x-y+z= 2x+5y+4z=0,3x+y-7z=0,则x+y-z=? 已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=? 已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3 已知x-y+z=0,3x+y-5z=0,则x+y+z/x+2y-3z=? 已知x-y+z=0.3x+y-5z=0,则x+y+z/x+2y-3z=_______ 2x+3y-4z=0.,3x+4y+5z=0,则x+y+z/x-y+z详细的解题过程 ﹛3x+2y+2z=140 5x+3y+3z=220 则x=?y=?z=?