9×9+99×99+999×999+9999×9999+9999+999+99+9=?等于多少?

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/23 11:40:46
9×9+99×99+999×999+9999×9999+9999+999+99+9=?等于多少?9×9+99×99+999×999+9999×9999+9999+999+99+9=?等于多少?9×9+

9×9+99×99+999×999+9999×9999+9999+999+99+9=?等于多少?
9×9+99×99+999×999+9999×9999+9999+999+99+9=?等于多少?

9×9+99×99+999×999+9999×9999+9999+999+99+9=?等于多少?
=(9*9+9)+(99*99+9)+(999*999+999)+(9999*9999+9999)
=9*(9+1)+99*(99+1)+999*(999+1)+9999*(9999+1)
=90+9900+999000+99990000
=100998990