3×999＋3＋99×8＋8＋2×9＋2＋9

更新时间：2021-07-15 08:53:17 98次访问

写清楚步骤，谢谢

3×999＋3＋99×8＋8＋2×9＋2＋9

= 3 × ( 999 + 1 ) + 8 × ( 99 + 1 ) + 2 × ( 9 + 1 ) + 9

= 3 × 1000 + 8 × 100 + 2 × 10 + 9

= 3000 + 800 + 20 + 9

= 3829

3×999＋3＋99×8＋8＋2×9＋2＋9

=3×(999+1)+8×(99+1)+2×(9+1)+9

=3×1000+8×100+2×10+9

=3000+800+20+9

=3829