Question

\(y=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}+\frac{1}{256}\)

Tính y

Chỉ có nhửng bạn có lời giải hay mình mới tick đúng

Answer 1

2y=\(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}\)

2y-y=1-\(\frac{1}{256}\)

y=\(\frac{255}{256}\)

Answer 2

\(\frac{255}{256}\)tik nhá ^_^ =))

Answer 3

  1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256

Quy đồng (MSC: 256). Ta có:

= 128/256+64/256+32/256+16/256+8/256+4/256+2/256+1/256

= 128+64+32+16+8+4+2+1/256

= 255/256