1/3+1/5+2/3+12/17-1/5+5/17=(1/3+2/3)+(1/5-1/5)+(12/17+5/17)=1+0+1=2选我啊望采纳
1/3+1/5+2/3+12/17-1/5+5/17=(1/3+2/3)+(1/5-1/5)+(12/17+5/17)=1+0+1=2
