应该是5/(3*7)+5/(7*11)+5/(11*15)+.+5/(55*59)的计算过程.对吗?
5/(3*7)+5/(7*11)+5/(11*15)+.+5/(55*59)
=5[4/(3*7)+4/(7*11)+4/(11*15)+.+4/(55*59)]/4
=5[(1/3-1/7)+(1/7-1/11)+(1/11-1/15)+.+(1/55-1/59)]/4
=5(1/3-1/7+1/7-1/11+1/11-1/15+.+1/55-1/59)/4
=5(1/3-1/59)/4
=5(59/177-3/177)/4
=5(56/177)/4
=5(14/177)
=70/177