3⼀5⼀(2-3⼀5-4⼀5)用简便方法

2025-03-07 00:44:27
推荐回答(1个)
回答1:

3/5/(2-3/5-4/5)
=3/5÷(2-7/5)
=3/5x1/2-3/5x5/7
=3/10-3/7
=-9/70