7/9+6/7+2/9-3/7=7/9+2/9+(改洞6/7-3/7)=1+3/滑歼笑7=10/信含7
7/9+6/磨禅7+2/瞎渗尘9-3/7=(7/9+2/9)+(6/7-3/7)=1+3/7=1又喊前3/7