(1) (-4- b)(b- 3)
(2) (x + 3)(2x + 3)
(3) (5 + b)(5 - 4b)
請列式加以解釋
代數式的展開和簡化
2009-08-05 5:18 am
回答 (2)
2009-08-05 5:41 am
✔ 最佳答案
(1)(-4- b)(b- 3)= -4(b – 3) – b(b – 3)
= -4b + 12 – b2 + 3b
= 12 – b – b2
(2) (x + 3)(2x + 3)
= x(2x + 3) + 3(2x + 3)
= 2x2 + 3x + 6x + 9
= 2x2 + 9x + 9
(3) (5 + b)(5 - 4b)
= 5(5 – 4b) + b(5 – 4b)
= 25 – 20b + 5b – 4b2
= 25 – 15b – 4b2
2009-08-05 5:59 am
仲以為係講taylor...
收錄日期: 2021-04-23 23:21:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090804000051KK02373