1/8+1/16+1/32+……1/512=(1\4-1\8)+(1\8-1\16)......(1\256-1\512)=1\4-1\8+1\8-1\16.....1\256-1\512=1\4-1\512=127/512
把分母全部化成512,然后就好算了
1/8+1/16+1/32+……1/512=(1/8+1/16+1/32+……1/512+1/512)-1/512=1/4-1/512=127/512
255/256