(对称多项式)因式分解:x(x+z)^2+y(z+x)^2+z(x+y)^2-4xyz
3个回答

估计是你题打错了,如果是对称多项式,应该是x(y+z)^2+y(z+x)^2+z(x+y)^2-4xyz

x(y+z)^2+y(z+x)^2+z(x+y)^2-4xyz

=x(y^2+2yz+z^2)+y(z^2+2xz+x^2)+z(x^2+2xy+y^2)-4xy

=xy^2+xz^2+yz^2+yx^2+zx^2+zy^2+6xyz-4xyz

=xy^2+xz^2+yz^2+yx^2+zx^2+zy^2+2xyz

=yx^2+zx^2+xy^2+xz^2+2xyz+yz^2+zy^2

=(y+z)x^2+(y^2+2yz+z^2)x+yz(y+z)

=(y+z)x^2+(y+z)^2x+yz(y+z)

=(y+z)[x^2+x(y+z)+yz]

=(y+z)(x+y)(x+z)

x^3+3x^2+4是无法分解因式的,可能是符号问题,这有一个

x^3-3x^2+4

=x^3-2x^2-x^2+4

=x^2(x-2)-(x^2-4)

=x^2(x-2)-(x+2)(x-2)

=(x-2)[x^2-(x+2)]

=(x-2)(x^2-x-2)

=(x-2)(x-2)(x+1)

=(x-2)^2(x+1)

x^4+2x^3-11x^2+12x+3b本人实在看不懂3b是什么意思

已知:a,b是实数,且满足a^3-a^2b-b^2+a=0,求证:a=b^2.

题目确实是有问题,将a=b^2代入原式有

b^6-b^5-b^2+b^2=0

即b^6=b^5?