① x+2y+3z=26 ②2x+3y+z=34③ 3x+2y+z=39

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 解方程组x+y/2=z+x/3=y+z/4①x+y+z=27② 2y+z=3y ① ,x+3y-z=8,② x+y+2z=13③ 求x,y,z 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 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 ①3x-4y+z=14x+5y+2z=172x+2y-z=3② x:y=3:2y:z=5:4x+y+z=66 ①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z-6=0③x/3=y/2 y/4=z/5 x+y+z=60三元一次方程 x/2=y/3=z/5 x+3y-z/x-3y+z x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 若x+y+z=3y=2z,则x/x+y+z=? ①5x-4y+4z=132x+7y-3z=193x+2y-z=18②y=2x-75x+3y+2z=23x-4z=4 已知x/2=y/4=z/7,求①x：y：z.②若2x+y+3z=58,分别求x,y,z的值.③求x+y/x+z的值. 3x+2y+z=39①2x+3y+z=34②x+2y+3z=26③要过程 ① x+2y+3z=26 ②2x+3y+z=34③ 3x+2y+z=39 ① x+2y+3z=26 ②2x+3y+z=34③ 3x+2y+z=29 过程! 解三元一次方程,①{x+y-z=0{ x+2y+z=13{2x-3y+2z=5②｛x+y-z=11｛y+z-x=5｛z+x-y=1③｛x+y=1｛y+z=6｛z+x=3