若x+y=-5,x+z=3,则(y+z)-(3-2x)的值为?

若x+y+z=3y=2z,则x/x+y+z=? 若3x+7y+z=5,4x+10y+z=3,则x+y+z=? 若x/2=y/3=z/4,则3x-2y+5z/x+y+z= 若x/3=y/2=z/5,则2x-3y-z/x-y+z= 若2x=3y=5z,则3x-2y+z/x+y-z 若x+y:y+z:z+x=3:4:5,则x:y:z=?(急,) x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z x/2=y/3=z/5 x+3y-z/x-3y+z 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= 若X:Y:Z=5:6:7那么(Y-X):(Y+Z)和(X+2Y+3Z):(3X+2Y+Z) 三元一次方程组题目x+y-z=11 y+z-x=5 x-y+z=1x+y=4 y+z=3 x+z=5若已知x-3y+2z=0 2x+3y-8z=0, 且xyz≠0,则x:y:z= (x+y-z)(x-y+z)= 若x/2=y/3=z/4则3x-2y+5z/x+y+x= 已知：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____. 若(x+y)/z=(y+z)/x=(x+z)/y 求（x+y-z)/(x+y+3z)的值 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 若X/10=Y/8=Z/9则X+Y+Z/Y+Z=? X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z