2.1乘以10.5的积减7.625除以2.5的商是多少?(要巧算的啊)
问题描述:
2.1乘以10.5的积减7.625除以2.5的商是多少?(要巧算的啊)
答
2.1×10.5-7.625÷2.5
=21/10×21/2-61/8÷5/2
=21×21/20-61/20
=441-60/20
=381/20
=19.05