x+y=-14 y+z=-7 x+z=19三元一次方程组的解

fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 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)=? x+y+z=14 7z=x+y+2 x+z=y (x+y-z)(x-y+z)= x+y+z=6 x+2y+3z=14 y+1=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. 解方程：x+z=y (1) ,7z-(x+y)=2 (2) ,x+y+z=14 (3) X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 14x+4y+z=200,x+y+z=100求解x,y,z x-4y+z=-302x+y-z=18x--y-z=7 {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1 实数X、Y、Z 满足X+Y=Z-1 ,XY=Z²－7Z+14.问 X平方+Y平方最大值?求解实数题：实数X、Y、Z 满足X+Y=Z-1 ,XY=Z²-7Z+14 1.问 X平方+Y平方最大值?2.Z 为何值时、X平方+Y平方取最小值? z+=x>y?++x: