sw百叶窗模具怎么画:数学:约分

来源:百度文库 编辑:高考问答 时间:2024/05/12 15:33:39
a^2+b^2-c^2+2ab
--------------- =
a^2-b^2-c^2-2bc

写出过程,谢谢

a^2+b^2-c^2+2ab
--------------- =
a^2-b^2-c^2-2bc

=[(a+b)^2-c^2]/[a^2-(b+c)^2]
=(a+b+c)(a+b-c)/(a+b+c)(a-b-c)
=(a+b-c)/(a-b-c)

a^2+b^2-c^2+2ab =a^2-b^2-c^2-2bc
2b^2+2ab+2bc =0
a+b+c =0 (b≠0)