X+Y=Z5X+5Z=803Y+5Z=70XYZ是等于几?

X+Y=Z5X+5Z=803Y+5Z=70XYZ是等于几? 3x一2y=11一5z2x+4y=9一3z5x一6y+7z=13 求xyZ的值 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 X/4=Y/5=Z/7则x+y+z/z=? {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1 x/2=y/3=z/5 x+3y-z/x-3y+z x+y+z=15 x+5y+10z=70 x,y,z,各是几? x+y+z=15 x+5y+10z=70 x,y,z,各是几? X+Y-Z=15 X+5Y+10Z=70 求：X、Y、Z fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 若X:Y:Z=5:6:7那么(Y-X):(Y+Z)和(X+2Y+3Z):(3X+2Y+Z) X+Y+Z=15 X+5Y+10Z=70,Y.Z的值 (x+y-z)(x-y+z)= x+Y+Z=1 X+3Y+7Z=-1 X+5Y+8Z=2x+Y+Z=1X+3Y+7Z=-1X+5Y+8Z=2 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. X-Y-Z=0 X+Y-3Z=4 2X-5Y+7Z=21