987654321×12345-987654322×12344的简便运算是什么QAQ

分类: 作业答案 • 2021-12-19 15:15:51

问题描述：

987654321×12345-987654322×12344的简便运算是什么
QAQ

答

设987654321=a, 12344=b
987654321×12345-987654322×12344
=a×﹙b+1)-(a+1)b
=ab+a-ab-b
=a-b
=987654321- 12344
=987641976

答

987654321×12345-987654322×12344
=987654321×12345-987654321×12344-12344
=987654321×（12345-12344）-12344
=987654321-12344
=987641977