这道题的简便算法

2025-05-16 09:07:18
推荐回答(1个)
回答1:

7/19x9/14+5/19x1/2
=9/19x7/14+5/19x1/2
=9/19x1/2+5/19x1/2
=(9/19+5/19)x1/2
=14/19x1/2
=7/19