9又19分之10乘2/31+2/19乘9/31 等于多少?

问题描述:

9又19分之10乘2/31+2/19乘9/31 等于多少?

9又19分之10乘2/31+2/19乘9/31
=9又19分之10乘2/31+9/19乘2/31
=2/31×(9又19分之10+9/19)
=2/31×10
=20/31

9又19分之10乘2/31+2/19乘9/31
=(10-9/19)×2/31+2/19*9/31
=20/31-9*19*2/31+2/19*9/31
=20/31