3x-6=-2(y+3z) 3(5z+y)=6-7z 4(x+y)=9+9z 求三元一次方程组

2(x+y-z)-3(x-y+z)-5(x+y-z)+6(x-y+z) 计算 x/2=y/3=z/5 x+3y-z/x-3y+z x+y+z=6 x+2y+3z=14 y+1=z 若X:Y:Z=5:6:7那么(Y-X):(Y+Z)和(X+2Y+3Z):(3X+2Y+Z) 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z {2x+3y-4z=-5 x+y+z=6 x-y+3z=10 x-y+z=-1 5x+2y-z=6 4x-3y+2z=-5 解方程组x+y+z=6 x+2y-3z=4 2x-y+z=5 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? x+y+z=1 4x+5y-z=6 x+2y-z=3 解方程组：x+y+z=4,x+y+2z=5,3x+y-z=6 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值 已知x/4=y/5=z/6,求x+y+z/3x-2y+z的值. 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z 1.{x:y:z=3:4:5 2x+3y-5z=-142.{x-y-z=-1 3x+5y+7z=11 4x-y+2z=-13.{x+y=1 x+z=0 2x+y+2z=44.{x-y+z=-3 2x-y-z=-2 -3x+y+z=-15.{x-y+z=-3 3x+y-4z=6 2x+y-z=36.{x-2y+5z=16 2x+y-5z=7 2x-y+z=38