巜谷梁传:帮做几道因式分解题

来源:百度文库 编辑:杭州交通信息网 时间:2024/04/30 15:02:58
要过程
(1)p^3-8
(2)a^3-8b^3+2a^2b-4ab^2

(1)p^3-8
=p^3-2p^2+2p^2-8
=p^2[p-2]+2[p^2-4]
=p^2[p-2]+2[p+2][p-2]
=[p-2][p^2+2p+4]
=[p-2][p+2]^2

(2)a^3-8b^3+2a^2b-4ab^2
=a^2[a+2b]-4b^2[a+2b]
=[a+2b][a^2-4b^2]
=[a+2b]^2[a-2b]

p^3-8=p^3-2^3=(p-2)(p^2+2p+2^2)