首页 > 留学知识库

问题: 小数题

1/2+1/4+1/8+1/16+1/32+1/64+1/128=

解答:

由题可知
1/128=1×1/128; 1/64=2×1/128; 1/32=4×1/128;
1/16=8×1/128; 1/8=16×1/128; 1/4=32×1/128;
1/2=64×1/128;
所以可以提取相同的因式1/128
所以
1/2+1/4+1/8+1/16+1/32+1/64+1/128
=1/128×(1+2+4+8+16+32+64)
=127/128