若x+y=8 y+z=12 x+z=10 则x+y+z =多少

若{x+3y+10z=0 则 (x+y-z)/(x-y+z) (x+y-z)(x-y+z)= X+Y+Z=? 若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x) 若x除以10=y除以8=z除以9,则x+y+z除以y+z f(x,y,z,w)=x*(x+y)*(x+y+z)*(x+y+z+w) 解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18 若x、y、z、满足（9/8）^x ×（10/9）^y×（16/5）^z=2,则x、y、z、的值为多少 若3x+7y+z=5,4x+10y+z=3,则x+y+z=? 若x+3y+5z=10,5x+z+3y=8,x+y+z=? x y z x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y---- 若xy-z不等于0,且(y+x)/x=(z+x)/y=(y+x)/z,求[(y+z)(z+x)(x+y)]/xyz的值?