计算(a+c+2b)(a+c-2b)

分类: 作业答案 • 2022-02-14 20:18:42

问题描述：

计算(a+c+2b)(a+c-2b)

答

(2/5-1/3)/ 5/6
=(6/15-5/15)/(5/6)
=1/15×6/5
=2/25
7.5+2.5/0.5
=7.5+5
=12.5
(4/5-2/3)/(1/2+2/3)
=(12/15-10/15)/(3/6+4/6)
=(2/15)/(7/6)
=2/15×6/7
=4/35

答

原式=(a+c)²-(2b)²
=a²+2ac+c²-4b²