x-y=-1 y-z=-1 x+y+z=6这个三元一次方程怎么解

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)(x-y+z)= {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1 x+y+z=6 x+2y+3z=14 y+1=z X/Y+Z=Y/X+Z+1=Z/X+Y-1=X+Y+Z,求x+y+z等于多少 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 有谁能帮俺解释一下++x||++y&&++z是什么意思啊?main(){int x,y,z (x,y,z);x=y=z=1; ++x||++y&&++z; printf(x=%d,y=%d,z=%d ,x,y,z) } 已知实数X.Y.Z满足(Y+Z)分之X+(Z+X)分之Y+(X+Y)分之Z=1,则(Y+Z)分之X平方+(Z+X)分之Y平方+(X+Y)分之Z平方的值为（ ） (x+y+z)÷10=x+1.1 y+x=z-80+y-1 z-y=8x+y+8 x+z÷y=? 分式加减的几道题目求速度1 .(x+y)²/（x-z)(y-z) - (y+z)²/（x-z)(y-z) = 2.2x+3y/x-y+2y/y-x-3y/x-y= 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 计算x/y+x=y/x+z+1=z/x+y-1的值 f(x,y,z)=In{[x^α+z^(1-α-β)]/y^β}+x/z+(z/x)^β,求 ∂f(x,y,z)/∂y