9999*9999怎么简便运算快回答我

问题描述:

9999*9999怎么简便运算
快回答我

9999*(10000-1)=99990000-9999=99980001

9999*9999
=(10000-1)(10000-1)
=100000000-20000+1
=99980001

9999 = 10000 -1
故:9999*9999 = (10000 -1) * (10000 -1)
= 100000000 - 20000 +1
= 99980001

9999x10000-9999=99990000-10000+1=99980001