如题所述
第1个回答 2016-03-17
=（100+1）x99=9900+99=9999;
=101x（100-1）=10100-101=9999.
=101x（100-1）=10100-101=9999.
第2个回答 2016-03-17
101x99
=（100+1）x99
=100x99+1x99
=9900+99
=9999
101x99
=（100+1）（100-1）
=100²-1²
=10000-1
=9999本回答被提问者采纳
=（100+1）x99
=100x99+1x99
=9900+99
=9999
101x99
=（100+1）（100-1）
=100²-1²
=10000-1
=9999本回答被提问者采纳
第3个回答 2016-03-17
101x99
=(100+1)(100-1)
=100x100-100+100-1
=10000-1
=9999
=(100+1)(100-1)
=100x100-100+100-1
=10000-1
=9999
