百度 我要提问3x+y+2z=28,5x-3y+z=7,试说明x+y+z=15

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 {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 2x+5y+4z=0,3x+y-7z=0,则x+y-z=? 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? x+y+z=2 x-3y+2z=1 2x+2y+z+5 要具体步骤.. 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 三元方程求救要过程2x+3y+z=383x+4y+2z=564x+5y+z=66x:y=5:3x:z=7:32x-y-z x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=? 已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值 已知3x=4y,2y=5z,试求x:y:z