\(\begin{array}{l}
+ )\,\,\,{2^x}.8 = 128\\
\,\,\,\,\,\,\,\,{2^x} = 128:8\\
\,\,\,\,\,\,\,\,{2^x} = 16\\
\,\,\,\,\,\,\,\,{2^x} = {2^4}\\
\,\,\,\,\,\,\,\,x = 4\\
+ )\,\,243:\,\,{3^x} = 27\\
\,\,\,\,\,\,\,\,{3^x} = 243:27\\
\,\,\,\,\,\,\,\,{3^x} = 9\\
\,\,\,\,\,\,\,\,{3^x} = {3^2}\\
\,\,\,\,\,\,\,\,x = 3
\end{array}\)