(x+3)(x-3)-(x+3)ˇ2 (xy+z)(-xy+z) (x+2y-1)(x-2y+1)
xy/x+y=1,yz/y+z=2,xz/x+z=3求x,y
如果1=xy/x+y,2=yz/y+z,3=xz/x+z,则x的值?
X+Y/XY=1,Y+Z/YZ=2,Z+X/ZX=3 求X的值
三元二次方程组(XY+X)/(X+Y+1)=2(XZ+2X)/(X+Z+2)=3(Y+1)(Z+2)/(Z+Y+3)=4
1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-
已知xy/x+y=3,yz/y+z=2,zx/z+x=1,求y的值
实数x、y、z满足x=6-3yx+3y-2xy+2z
已知xy/x+1=1 yz/y+z=2 zx/z+x=3 求x
已知x>0,y>0,z>0,证明x^3/(x+y)+y^3/(y+z)+z^3/(z+x)≥(xy+xz+yz)/2
化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+(z-y)(x-y)/(xy-2z)(y+z-2x)+(x-
一道数学题,已知x+y+z=1,x^2+y^2+z^2=2,问xy+yz+zx,x^3+y^3+z^3
已知x+y+z=3,xy+yz+xz=-1,xyz=2,求x^2y^2+y^2z^2+x^2z^2