①:2×一y+3z=3,②:3x+y一2z=-1,③:x+y+z=5;
①:2×一y+3z=3,②:3x+y一2z=-1,③:x+y+z=5;
解三元一次方程组:(一)2x+y+z=4① x-y+3z=3 ②x+z=2③ 二;①2x+y+z=2 ②x+2y+z=5
解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
x/2=y/3=z/5 x+3y-z/x-3y+z
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
解方程组 2x一y十3z=3 3x十y一2Z=-1 x十y十Z=5
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
解方程:x十y十Z=4,2x一y十Z=3,3x一2y一3Z=-5,
一、用代入法解下列方程组 1、{x+y+z=2,3x-y-4z=5 ,2x+3y-2z=0}
{5x+2y-4z=1① 3x-3y+2z=1② -2x+3y-2z=0③}
x+y+z=2 ① 2x+3y+z=38 ① x+y=3 3x-y-4z=5 ② 3x+4y+2z+56 ② y+z=5