5x+3y=25,2x+7y-3z=19,3x+2y-z=18,求x,y,z的值

5x+3y=25,2x+7y-3z=19,3x+2y-z=18,求x,y,z的值 {x+y+z=1 {x+3y+7z=2 {x+5y+19z=4 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z x/2=y/3=z/5 x+3y-z/x-3y+z 2x+3y-z=11 2x+y-5z=8 -2+7y+z=19 若X:Y:Z=5:6:7那么(Y-X):(Y+Z)和(X+2Y+3Z):(3X+2Y+Z) 1.5x-3y+z=25x+2y-4z=3-5y+y-z=2以上是第一题.2.x+y=-2x+z=13y+z=1以上是第二题.3.x-y-z=-13x+5y+7z=114x-y+2z=-1以上是第三题. {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 解下列方程 三元一次方程一、 5x-3y+z=25x+2y-4z=3-5x+y-z=2二、x+y=-2x+z=13y+z=1三、x-y-z=-13x+5y+7z=114x-y+2z=-1第二题不用了 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=1 X+3Y+7Z=-1 X+5Y+8Z=2x+Y+Z=1X+3Y+7Z=-1X+5Y+8Z=2 六年级三元一次方程组.解下列方程组：(1)5x-3y+z=25x+2y-4z=3-5x+y-z=2(2)x-y-z=-13x_5y+7z=114x-y+2z=-1(3)9x-5y+z=-69x+y+4z=3-9x+3y-5z=0(4)x+y=22x+z=-27y+z=13 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) ｛ 5x-3y+z=25x+2y-4z=3-5x+y-z=2 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 3x-y=-7,y+2z=2,2x-2z=-5 求x,y,z x+y+z=0,3x-2y-2z=5,y-z=2x-7