3/15+5/8+3/8+8/13= 12-(2/3-1/2)=

问题描述:

3/15+5/8+3/8+8/13= 12-(2/3-1/2)=

3/15+5/8+3/8+8/13
错了吧
应该是5/13+5/8+3/8+8/13
=(5/13+8/13)+(5/8+3/8)
=1+1=2
12-(2/3-1/2)
=12-1/6
=11又5/6