\(\left(\frac{1}{2}\right)^{2x-1}=\frac{1}{8}\)
=> \(\left(\frac{1}{2}\right)^{2x-1}=\left(\frac{1}{2}\right)^3\)
=> \(2x-1=3\)
=> \(2x=3+1\)
=> \(2x=4\)
=> \(x=4:2\)
=> \(x=2\)
Vậy \(x=2.\)
Chúc bạn học tốt!
Đề này mới đúng chứ ?
\(\left(\frac{1}{2}\right)^{2x-1}=\frac{1}{8}\)
\(\Leftrightarrow\left(\frac{1}{2}\right)^{2x-1}=\left(\frac{1}{2}\right)^3\)
\(\Leftrightarrow2x-1=3\)
<=> 2x=4
<=>x=2
*Bài làm:
~Ta có: \(\left(\frac{1}{2}\right)^{2x-1}\) = \(\frac{1}{8}\)
⇒ \(\left(\frac{1}{2}\right)^{2x}\) : \(\left(\frac{1}{2}\right)^1\) = \(\frac{1}{8}\)
⇒ \(\left(\frac{1^2}{2^2}\right)^x\) : \(\frac{1}{2}\) = \(\frac{1}{8}\)
⇒ \(\left(\frac{1}{4}\right)^x\) = \(\frac{1}{8}\) . \(\frac{1}{2}\)
⇒ \(\left(\frac{1}{4}\right)^x\) = \(\frac{1}{16}\)
⇒ \(\left(\frac{1}{4}\right)^x\) = \(\left(\frac{1}{4}\right)^2\)
⇒ \(x\) = \(2\) .
~Vậy: \(x\) = \(2\) .
➤ Chúc bạn học tốt!