Question

Vă rog urgent! Repede vă rogg!! ​

Answer 1

Răspuns:

$\frac{7}{8}$

Explicație pas cu pas:

$2^{-1}+2^{-2}+2^{-3}=\frac{1}{2^{1}}+\frac{1}{2^{2}}+\frac{1}{2^{3}}=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}=\frac{4}{8}+\frac{2}{8}+\frac{1}{8}=\frac{4+2+1}{8}=\frac{7}{8}$