21×12+21×87+21=简便计算?

2025-02-24 20:30:58
推荐回答(2个)
回答1:

=21×(12+87+1)
=21×100
=2100
认为简便计算过程。

回答2:

21×12+21×87+21
=21×12+21×87+21×1
=21×(12+87+1)
=21×100
=2100
望采纳