Maths problem: how to do blue line, thanks?
回答 (1)
2020-01-15 8:51 pm
✔ 最佳答案
(a) (i) 25a²-5ab-2b² = (5a+b)(5a-2b)
(ii) 125a³+b³ = . . . = (5a+b)(25a²-5ab+b²)
(b)
125a³-15ab²-2b³
= (125a³+b³)-15ab²-3b³
= (5a+b)(25a²-5ab+b²) - 3b²(5a+b) - - - - → From (a)(ii)
= (5a+b)(25a²-5ab-2b²)
= (5a+b)(5a+b)(5a-2b) - - → From (a)(i)
= (5a+b)²(5a-2b)
收錄日期: 2021-04-24 07:43:37
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https://hk.answers.yahoo.com/question/index?qid=20200115094643AAqLcmz