Hoặc
Cách phía trên là cách lớp 5 nhé
Ta có:\(\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{1}{16}+\dfrac{1}{32}+\dfrac{1}{64}\)
\(=\dfrac{32}{64}+\dfrac{16}{64}+\dfrac{8}{64}+\dfrac{4}{64}+\dfrac{2}{64}+\dfrac{1}{64}=\dfrac{63}{64}\)
Ta có:\(\dfrac{5083}{2431}=\dfrac{23}{11}\)
1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64
= 32/64 + 16/64 + 8/64 + 4/64 + 2/64 + 1/64
= 63/64
5083/2431 = 21/11
\(\dfrac{5083}{2431}=\dfrac{23}{11}\)
tính nhanh p/s 1+ 5/4 + 5/8 + 5/16 + 5/32 + 5/64
