Tính nhanh 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 Sosssssssssssssssssssssssss giải nhanh lên em tui còn

2 bình luận về “Tính nhanh 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 Sosssssssssssssssssssssssss giải nhanh lên em tui còn”

1.     $\frac{1}{2}$ $+$ $\frac{1}{4}$ $+$ $\frac{1}{8}$ $+$ $\frac{1}{16}$ $+$ $\frac{1}{32}$ $+$ $\frac{1}{64}$ $+$ $\frac{1}{128}$

   $=$ $\frac{1}{1×2}$ $+$ $\frac{1}{2×4}$ $+$ $\frac{1}{4×8}$ $+$ $\frac{1}{8×16}$ $+$ $\frac{1}{16×32}$ $+$ $\frac{1}{32×64}$ $+$ $\frac{1}{64×128}$

   $=$ $\frac{1}{1}$ – $\frac{1}{2}$ + $\frac{1}{2}$ $-$ $\frac{1}{4}$ + $\frac{1}{4}$ – $\frac{1}{8}$ + $\frac{1}{8}$ – $\frac{1}{16}$ + $\frac{1}{16}$ – $\frac{1}{32}$ + $\frac{1}{32}$ – $\frac{1}{64}$ + $\frac{1}{64}$ – $\frac{1}{128}$

   = $\frac{1}{1}$ – $\frac{1}{128}$

   = $\frac{128}{128}$ – $\frac{1}{128}$

   = = $\frac{127}{128}$

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2. Giải đáp:

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

   =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

   =1-1/128

   =128/128-1/128

   =127/128

    

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