(5a+6b-7c)^2-(5a-6b+7c)^2

分类: 作业答案 • 2023-01-19 07:30:44

问题描述：

答

(5a+6b-7c)^2-(5a-6b+7c)^2
=[(5a+6b-7c)-(5a-6b+7c)]×[(5a+6b-7c)+(5a-6b+7c)]
=(12b-14c)×10a
=20a(6b-7c)