x+y+z=12(x=1-6 y=1-6 z=1-6)有多少种排列?可以的话能不能教下我怎么算比较容易算?

x+y+z=6 x+2y+3z=14 y+1=z 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? 12y+9z=x,6(y+1/4)+9z=x,y+z=x 解方程 x(x+y+z)=6 y(x+y+z)=12 z(x+y+z)=18 解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18 方程组3x+y-4z=1 2x-y-2z=6 5x+3y-3z= --1/2{负二分之一} x=?y=?z=?3x+2y+z=13 x+y+2z=7 2x+3y-z=12 x=?y=?z=? (1)X+Y=15,Y+Z=-6,Z+X=7.(2)X+Y=-14,Y+Z=-7,Z+X=9.(3)X+Y=0,Y+Z=-1,Z+X=-1. {x-y+z=6,x+3y=-1,y+2z=3 已知x:y=3:5 y:z=6:1,求x:y:z( ):( ):( ) 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, x-y+z=-1 5x+2y-z=6 4x-3y+2z=-5 x+y-z=6 x-3y+2z=1 3x+2y-z=4 阿 x+y+z=1 4x+5y-z=6 x+2y-z=3 x+y-z=6,x-3y+2z=1,3x+2y-z=4 x+y-z=6 x-3y+2z=1 3x+2y-z=4 x=2y-9z x+2y-3z=2 x-2y+6z=1 x+y-z=6 x-3y+2z=1 3x+y-z=4 三元一次方程组(1)x-2y=-9 y-z=3 2z+x=47 (2)3x-y+z=4 2x+3y-z=12 x+y+z=6