如题所述
第1个回答 2018-05-01
1/2+3/4+7/8+15/16+31/32+63/64+127/128
=(1-1/2)+(1-1/4)+...+(1-1/128)
=7- (1/2+1/4+...+1/128)
=7 - [ 1 - (1/2)^7 ]
=6 + 1/128
=769/128
=(1-1/2)+(1-1/4)+...+(1-1/128)
=7- (1/2+1/4+...+1/128)
=7 - [ 1 - (1/2)^7 ]
=6 + 1/128
=769/128
第2个回答 2018-05-01
1/2+3/4+7/8+15/16+31/32+63/64+127/128=
64/128+96/128+112/128+120/128+124/128+126/128+127/128=
769/128=
6又1/128
64/128+96/128+112/128+120/128+124/128+126/128+127/128=
769/128=
6又1/128
