x+y+z+=813x+y=17y=4z是一道应用题..足球比赛公八场，积分规则：胜一场得三分..平一场得一分，负一场得零分，这场比赛中，六一班所平的场数是所负的场数地2倍，总得分17分，他们胜几场.负几

(x+y-z)(x-y+z)= X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+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)=? (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 x+y/2=z+x/3=y+z/4 x+y+z=27 x-4y+z=-302x+y-z=18x--y-z=7 14x+4y+z=200,x+y+z=100求解x,y,z x+2y=3x+2z=4y+z 求x:y:z x=y; y=z; z=x/y 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= (x*x+2)(y*y+4)(z*z+8)=64xyz,求x,y,z x-y-z=0 4x+8y+z=17 z=1 用行列式的性质证明：y+z z+x x+y x y z x+y y+z z+x =2 z x y z+x x+y y+z y z x 这个怎么证? z+=x>y?++x: fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 (x-2y+z)(x+y-2z)分之（y-x)(z-x) + (x+y-2z)(y+z-2x)分之(z-y)(x-y) + (y+z-2z)(x-2y+z)分之（x-z)(y-z)=?第三部分那个是 （y+z-2x)(x-2y+z)分之（x-z)(y-z) x/(y+z+u)=y/(z+u+x)=z/(u+y+x)=u(x+y+z)求(x+y)/(z+u)+(y+z)/(y+x)+(z+y)/(x+y)+(u+x)/(z+y)