35分之3+63分之3+99分之1+143分之1
=（1/5-1/7+1/7-1/9)x3/2+(1/9-1/11+1/11-1/13）x1/2
=（1/5-1/9）x3/2+(1/9-1/13)x1/2
=4/45x3/2+4/117x1/2
=2/15+2/117
=2/3x(1/5+1/39)
=2/3x44/195
=88/585
希望能帮你忙,懂了请采纳,