\(\left(\frac{3}{4}\right)^{3x}=\frac{81}{256}\)
\(\left(\frac{3}{4}\right)^{3x}=\left(\frac{3}{4}\right)^4\)
\(3x=4\)
\(x=\frac{4}{3}\)
Chúc bạn học tốt ^^
\(\left(\frac{3}{4}\right)^{3x-1}=\frac{81}{256}\)
\(\left(\frac{3}{4}\right)^{3x-1}=\left(\frac{3^4}{4^4}\right)\)
\(\left(\frac{3}{4}\right)^{3x-1}=\left(\frac{3}{4}\right)^4\)
\(\Rightarrow3x-1=4\)
\(\Rightarrow3x=5\)
\(\Rightarrow x=\frac{5}{3}\)
phương an đề là :
\(\left(\frac{3}{4}\right)^{3x-1}=\frac{81}{256}\) mà
\(\left(\frac{3}{4}\right)^{3x-1}=\frac{81}{256}\)
\(\Leftrightarrow\left(\frac{3}{4}\right)^{3x-1}=\left(\frac{3}{4}\right)^4\)
\(\Leftrightarrow3x-1=4\)
\(\Leftrightarrow3x=5\)
\(\Leftrightarrow x=\frac{5}{3}\)
bn ghi đề dzậy ai mà hỉu đc, lúc đầu còn tưởng đề sai -_-
\(\left(\frac{3}{4}\right)^{3x-1}=\frac{81}{256}\)
\(\Rightarrow\left(\frac{3}{4}\right)^{3x-1}=\left(\frac{3}{4}\right)^4\)
\(\Rightarrow3x-1=4\)
\(\Rightarrow3x=1+4\)
\(\Rightarrow3x=5\)
\(\Rightarrow x=5:3\)
\(\Rightarrow x=\frac{5}{3}\)
Vậy \(x=\frac{5}{3}\)
