急x+y+z=36,0.5x+y+2/3z=20,10x+7y+6z=183

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) (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 1.已知x:y:z=4:5:7,求：（一）2x+3y+z/5z； （二）x+y/y+z 非常急, 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 已知3X+7Y+Z=6 4X+10Y+z=7 求X+Y+Z=? x+y+z=4 2x+3y-z=6 3x+2y+2z=10 3x+7y+z=5 ,4x+10y+z=6 ,x+y+z= {2x+3y-4z=-5 x+y+z=6 x-y+3z=10 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z