99×39+39的简便计算怎么算、

问题描述:

99×39+39的简便计算怎么算、

因为39=39×1
所以99×39+39
=99×39+39×1
=(99+1)×39
=100×39
=3900

100*39

99×39+39
=99×39+39×1
=39×(99+1)
=39×100
=3900