（a+2b+1)(a-2b+1)=?
回答 (2)
2019-07-12 7:23 pm
Sol
(a+2b+1)(a－2b+1)
=(a+1+2b)(a+1－2b)
=(a+1)^2－(2b)^2
=a^2+2a+1－4b^2
(a+2b+1)(a－2b+1)
=(a+1+2b)(a+1－2b)
=(a+1)^2－(2b)^2
=a^2+2a+1－4b^2
2019-07-14 12:56 am
(a + 2b + 1)(a - 2b + 1)
= [(a + 1) + 2b][(a + 1) - 2b]
= (a + 1)² - (2b)²
= a² - 4b² + 2a + 1 #
= [(a + 1) + 2b][(a + 1) - 2b]
= (a + 1)² - (2b)²
= a² - 4b² + 2a + 1 #
收錄日期: 2021-04-30 22:50:40
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20190712105604AANwgjC