找规律,填空: ①101+102+103+104+105=_×_ ②11+13+15+17+19+21+23=(_+_)×3+_.
问题描述:
找规律,填空:
①101+102+103+104+105=______×______
②11+13+15+17+19+21+23=(______+______)×3+______.
答
①101+102+103+104+105
=(101+2)+(102+1)+103+103+103
=103+103+103+103+103
=103×5;
②11+13+15+17+19+21+23
=(11+23)+(13+21)+(15+19)+17
=34+34+34+17
=34×3+17
=(11+23)×3+17
故答案为:103,5;11,23,17.