题目内容
x3(y-z)+y3(z-x)+z3(x-y)
考点:因式分解
专题:
分析:首先将原式添项,进而重新分组,进而利用立方差公式以及提取公因式法分解因式即可.
解答:解:x3(y-z)+y3(z-x)+z3(x-y)
=x3(y-z)+y3(z-x)-z3(y-z)-z3(z-x)
=(x3-z3)(y-z)+(y3-z3)(z-x)
=(x-z)(y-z)(x2+xz+z2)-(x-z)(y-z)(y2+yz+z2)
=(x-z)(y-z)(x2+xz-y2-yz)
=(x-z)(y-z)[(x-y)(x+y)+(x-y)z]
=(x-y)(x-z)(y-z)(x+y+z).
=x3(y-z)+y3(z-x)-z3(y-z)-z3(z-x)
=(x3-z3)(y-z)+(y3-z3)(z-x)
=(x-z)(y-z)(x2+xz+z2)-(x-z)(y-z)(y2+yz+z2)
=(x-z)(y-z)(x2+xz-y2-yz)
=(x-z)(y-z)[(x-y)(x+y)+(x-y)z]
=(x-y)(x-z)(y-z)(x+y+z).
点评:此题主要考查了因式分解法的应用,正确进行添项以及利用立方差公式分解因式是解题关键.
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