#### Answer

$x=6$

#### Work Step by Step

Re-write the given equation as: $(3^2)^{-x+15}=(3^3)^x$
or, $3^{-2x+30}=3^{3x}$
Use the rule power rule: $a^p=a^q$.
We can see that the base $a=2$ is the same on both sides of the equation.
So, the exponents will also be equal.
This implies that $p=q$
Therefore, $ -2x+30=3x \\ 30=5x \\ x =6$