S = 1 + 1/2 + 1/4 + 1/8 + .....................1/128 + 1/256
= 1 + (1 – 1/2) + (1/2 – 1/4) + (1/4 – 1/8) + ....................... (1/128 – 1/256)
= 2 – 1/256 = 511/256
Vậy S = 511/256
Tính:
A= 1/2+1/4+1/8+1/16+1/64+1/128+1/256
Tính nhanh : 1+1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256+1/512
Tính nhanh
1/2 + 1/4 + 1/8 +................ + 1/128 + 1/256
Tính nhanh
1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256
Tính nhanh:
1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256
Tính nhanh
1/2+1/4+1/8+1/18+1/32+1/64+1/128+1/256
viết kết quả bài toán sau:
1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256+1/152.
kết quả của dãy tính:
1/2+1/4+1/8+1/16+....+1/128+1/256+1/512=.......?
tính nhanh p/s 1+ 5/4 + 5/8 + 5/16 + 5/32 + 5/64
b) 1/3 +1/9 + 1/27 + 1/81 +...........+ 1/59049
c) 3/2 + 3/8 + 3/32 +3/128 + 3/512
d) 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 giúp mình với 
