First, notice that 9 = 32. Then the term on the left can be rewritten as (32)x. Using the rules of powers, that becomes 32x.
The term on the right is already a power of 3 -- there, the power is x2 - 4x.
Since both sides are expressed as powers of 3, you can ignore the 3 and set the exponents equal to each other.
We have: 2x = x2 - 4x
We can rearrange this into a quadratic equation: x2 - 6x = 0, or
x(x - 6 ) = 0
Setting each factor equal to 0, we get:
x = 0 or x = 6