八分之九减(六分之五减九分之七)等于多少?

2025-12-25 08:49:47
推荐回答(3个)
回答1:

八分之九减 (六分之五减九分之七) = 8/9 - (6/5 - 9/7)
先算括号里的部分:
6/5 - 9/7 = (6/5) * (7/9) - 9/7 = (6 * 7)/(5 * 9) - 9/7 = 42/45 - 9/7
然后算整个式子:
8/9 - 42/45 + 9/7 = (8 * 45 - 42 * 9)/(9 * 45) = (360 - 378)/405 = -18/405
所以结果为:
八分之九减 (六分之五减九分之七) = -18/405

回答2:

解:原式=9/8-(5/6-7/9)
=9/8-(15/18-14/18)
=9/8-1/18
=81/72-4/72
=77/72
=1又5/72

回答3:

9/8-(5/6-7/9)
=9/8-(15/18-14/18)
=9/8-1/18
=81/72-4/72
=77/72