若2X－3Y＋4Z=2,4X+3Y+2Z=4,则X+Y=多少

x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 2x+z=10 x+y-z=4 3x-y-z=0 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 若x/2=y/3=z/4,则3x-2y+5z/x+y+z= 若x:y:z=2:3:4,求x+y+z/x-2y+3z的值 若x/3=y/4=z/5,求x+y+z/3x-2y+z的值. 若x/2=y/3=z/4不等于0,求x+y+z/x+y-z的值 若xyz≠0且4(x/z)-5(y/z)=-2,(x/z)+4(y/z)=3,求x:y:z (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 化简-(-3x-y+2z)-{-x+【4x-(x-y-z)-3x+2z} 若X Y Z 满足方程组 X-2Y＋3Z＝0 2X-3Y＋4Z＝0 则 X：Y：Z ＝? 若(4x-3y-3z)^2+|x-3y-z|=0 且xyz不等于0 则4x+y-z/x+y+z 的值 若4x-3y-6z=0,x+2y-7z=0,则x+y+z/3x-y+z=? 若x+y+z=3y=2z,则x/x+y+z=? 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= 已知x:：y：z=3：4：5,(1)求x+y分之z的值；（2）若x+y+z=6,求x,y,z. 数学--整式运算4(x-y+z)-2(x+y-z)-3(-x-y-z)