The question is posted in Wrong subject category. Anyways, the solution is stated below:
[tex] \frac{1}{36}= 6^{x-3} \\ \\
\frac{1}{ 6^{2} }= 6^{x-3} \\ \\
6^{-2}=6^{x-3}[/tex]
The base on both sides are same i.e. 6. For the equation to be true, the exponents(powers) must also be the same. So this means
[tex]-2 = x-3 \\ \\
x = 1[/tex]
Therefore, answer to this question is x = 1