哈尔滨烟草公司招聘:因式分解

来源:百度文库 编辑:查人人中国名人网 时间:2024/04/28 15:29:48
1. x立方-3px平方+(3p平方-q平方)x-p(p平方-q平方)
(所有平方、立方均是指左边那个字母)

x^3-3px^2+(3p^2-q^2)x-p(p^2-q^2)
=x^3-3px^2+2xp^2+(p^2-q^2)x-p(p^2-q^2)
=x(x^2-3px+2p^2)+(p^2-q^2)(x-p)
=x(x-p)(x-2p)+(p^2-q^2)(x-p)
=(x-p)[x(x-2p)+(p^2-q^2)]
=(x-p)[x^2-2px+p^2-q^2]
=(x-p)[(x-p)^2-q^2]
=(x-p)(x-p+q)(x-p-q)