\(\left(\frac{2}{3}\right)^x=\frac{16}{81}\)
\(\left(\frac{2}{3}\right)^x=\left(\frac{2}{3}\right)^4\)
\(\Rightarrow x=4\)
\(\left(\frac{2}{3}\right)^x=\frac{16}{81}\)
\(\Leftrightarrow\left(\frac{2}{3}\right)^x=\left(\frac{2}{3}\right)^2\)
\(\Leftrightarrow x=2\)
k mình nha bạn