99乘以9加98怎么样简便运算?
问题描述：
99乘以9加98怎么样简便运算?
答
99*9+98
=99*9+99-1
=99*(9+1)-1
=990-1
=989
99乘以9加98怎么样简便运算?
99*9+98
=99*9+99-1
=99*(9+1)-1
=990-1
=989