> 数学 >
找规律并证明:15*15=1*2*100+25=225,25*25=2*3*100+25=625
人气:105 ℃ 时间:2019-08-21 20:39:46
解答
即(10n+5)*(10n+5)=n*(n+1)*100+25
证明
(10n+5)*(10n+5)
=10n(10n+5)+5(10n+5)
=100n²+50n+50n+25
=100n²+100n+25
=n*(n+1)*100+25
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版