5/7-4/15+1/15+2/7= 26*3/4-14*3/4= 24*(5/12-1/4+5/6)= 6.5*2/7+3.5*2/7=
问题描述：
5/7-4/15+1/15+2/7= 26*3/4-14*3/4= 24*(5/12-1/4+5/6)= 6.5*2/7+3.5*2/7=
答
1.=5/7+2/7+(1/15-4/15)=1-1/5=4/5
2.=(26-14)*3/4=12*3/4=9
3.=5/12-3/12+10/12=12/12=1
4.=(6.5+3.5)*2/7=20/7