(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34的简便算是多少
问题描述:
(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34的简便算是多少
答
1、这道题要用“假设法”来做.2、假设:1+0.23+0.34=a; 0.23+0.34=b;(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)=a×(b+0.65)-(a+0.65)×b=ab+0.65a-ab-0.65b=0.65×(a-b)……...