观察:(1)14*16=224=1*(1+1)*100+4*6, (2)23*27=621=2*(2+1)*100+3*7, (3)32*38=1216=3*(3+1)*100+2*8

2025-02-23 00:25:40
推荐回答(2个)
回答1:

(10n+a)*(10n+b)=100n^2+10n(a+b)+ab=n(n+1)*100+a*b

回答2:

(10n+a)(10n+b)
=100n^2+10n(a+b)+ab
=100n^2+100n+ab
=n(n+1)*100+a*b