Question

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

Answer 1

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

=64/128+32/128+16/128+8/126+4/126+2/126+1/128

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

=123/128

Answer 2

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

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

C=1-1/128

C=127/128

Answer 3

127/128 nha bạn!