{3x-y=-7 y+4z=3 2x-2z=-5 {a:b:c=3:4:5 a+b+c=36 {x+y+z=0 4x+2y+z=3 9x+3y+z=6{x+y-z=11 y+z-x=5 z+x-y=1总共是四个三元一次方程组,一个大扩号后是一个题,扩号后面要么三个式子要么两个式子,每个式子中间有空格隔开

x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 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 解方程：{2x+3y+z=7,x+y+z=4,3x+y-z=-4{2x+3y+z=7,x+y+z=4,3x+y-z=-4要过程 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? x：y：z=3:4:7 2x-3y+z=18 求：3x-2y+z x+2y+4z=17 2x+y+z=7 3x+y+2z=11 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? X-Y-Z=0 X+Y-3Z=4 2X-5Y+7Z=21 3x+7y+4z=35,x+5y+2z=40,x+y+z=( ) {x+y+z=1 {x+3y+7z=2 {x+5y+19z=4 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 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 {5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=-1 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 X-Y-Z=7 ③4x+4y+2z=7 6X-4y-z=6 2x-y+z=1 已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值