a) \(\left(\frac{1}{9}\right)^x=\left(\frac{1}{27}\right)^{22}\)
\(\left[\left(\frac{1}{3}\right)^2\right]^x=\left[\left(\frac{1}{3}\right)^3\right]^{22}\)
\(\left(\frac{1}{3}\right)^{2\cdot x}=\left(\frac{1}{3}\right)^{66}\)
\(\Rightarrow2\cdot x=66\)
\(x=66\div2\)
\(x=33\)
Vậy x = 33
b) \(\left(\frac{4}{9}\right)^x=\left(\frac{8}{27}\right)^6\)
\(\left[\left(\frac{2}{3}\right)^2\right]^x=\left[\left(\frac{2}{3}^3\right)\right]^6\)
\(\left(\frac{2}{3}\right)^{2\cdot x}=\left(\frac{2}{3}\right)^{18}\)
\(\Rightarrow2\cdot x=18\)
\(x=18\div2\)
\(x=9\)
Vậy x = 9