Letter A
For negative exponents
Therefore, when the exponent is negative, the base is inverted and the sign of the exponent is changed.
Letter B
Here it is necessary to convert the numbers in the power of 3 and after applying exponent rules
[tex]\begin{gathered} 27\cdot9^{3x}=3^k \\ 3^3\cdot(3^2)^{3x}=3^k \\ 3^3\cdot^{}3^{6x}=3^k \\ 3^{(3+6x)}=3^k \\ k=3+6x \end{gathered}[/tex]
