x+y+z=a…x平方+y平方+z平方=b平方…x立方+y立方+z立方=c立方…求xyz
问题描述：
x+y+z=a…x平方+y平方+z平方=b平方…x立方+y立方+z立方=c立方…求xyz
答
x+y+z=ax^2+y^2+z^2=b^2x^3+y^3+z^3=c^3(x+y+z)^2=x^2+y^2+z^2+2xy+2xz+2yz=a^22xy+2xz+2yz=a^2-b^2(x+y+z)(xy+xz+yz)=yx^2+zx^2+xy^2+zy^2+xz^2+yz^2+3xyz=a(a^2-b^2)/2(x+y+z)(x^2+y^2+z^2)=x^3+y^3+z^3+yx^2+zx^2...