Question

mọi người giúp mình câu 2d,f và câu 3c nhé

Answer 1

Bài 2: 

d: \(\left(\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{1}{16}\right):x=\dfrac{1}{2}+\dfrac{1}{6}+...+\dfrac{1}{132}\)

\(\Leftrightarrow\dfrac{8+4+2+1}{16}:x=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{11}-\dfrac{1}{12}\)

\(\Leftrightarrow\dfrac{15}{16}:x=\dfrac{11}{12}\)

hay x=45/44

f: \(\left(x+\dfrac{1}{2}\right)+\left(x+\dfrac{1}{4}\right)+\left(x+\dfrac{1}{8}\right)+\left(x+\dfrac{1}{16}\right)=1\)

=>4x+15/16=1

=>4x=1/16

hay x=1/64