简便计算1/2+1/4+1/8+1/16+1/32+1/64+1/128

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简便计算1/2+1/4+1/8+1/16+1/32+1/64+1/128

简便计算1/2+1/4+1/8+1/16+1/32+1/64+1/128
简便计算1/2+1/4+1/8+1/16+1/32+1/64+1/128

简便计算1/2+1/4+1/8+1/16+1/32+1/64+1/128
原式+1/128=1
所以原式=127/128

先算前两项,结果再加第三项,规律一眼就可以看出,答案是128分之127

1/2+1/4+1/8+1/16+1/32+1/64+1/128
=1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/128-1/128
=1/2+1/4+1/8+1/16+1/32+1/64++1/64-1/128
=1/2+1/4+1/8+1/16+1/32+1/32-1/128
=........
=1-1/128
=127/128

原式=1-1+1/2+1/4+1/8+1/16+1/32+1/64+1/128
=1-1/2+1/4+1/8+1/16+1/32+1/64+1/128
=1-1/4+1/8+1/16+1/32+1/64+1/128
。。。。
=1-1/128
=127/128