Olá,
[tex] \tt \: 2 \cdot \: {9}^{x} = 54 \\ \tt \: {9}^{x} = \frac{54}{2} \\ \tt \: {9}^{x} = 27 \\ \tt \left( {3}^{2} \right) {}^{x} = {3}^{3} \\ \tt \: {3}^{2x} = {3}^{3} \\ \tt \: { \cancel3}^{2x} = { \cancel3}^{3} \\ \tt 2x = 3 \\ \tt \: x = \frac{3}{2} \\ [/tex]
