99*39+39= (递等式简便计算)
问题描述:
99*39+39= (递等式简便计算)
答
99*39+39
= (99+1)*39
=100*39
=3900
99*39+39= (递等式简便计算)
99*39+39
= (99+1)*39
=100*39
=3900