820-5.78x99+5.98用简便方法

820-5.78x99+5.98用简便方法
2024-12-16 22:41:25
推荐回答(1个)
回答1:

820-5.78x99+5.98
=820-5.78x(99+1)
=820-5.78x100
=820-578
=242