[tex]\it 3^{2-x}=\dfrac{1}{9} \Rightarrow 3^{2-x}=\dfrac{1}{3^2} \Rightarrow \dfrac{3^{2-x}}{1}=\dfrac{1}{3^2} \Rightarrow 3^2\cdot3^{2-x}=1 \Rightarrow 3^{2+2-x}=1 \Rightarrow\\ \\ 3^{4-x}=3^0 \Rightarrow4-x=0 \Rightarrow x=4[/tex]
