So we need to solve:
3ˣ⁻¹ = 9ˣ⁺²
To do this, we need to have the same base for both sides of the equation.
So let's go with the base of 3.
3² = 9
3ˣ⁻¹ = (3²)ˣ⁺²
3ˣ⁻¹ = 3²ˣ⁺⁴
Since the bases are the same now, we need to get rid of them and we would get:
x - 1 = 2x + 4
Subtract both sides by 2x:
-x - 1 = 4
Add 1 to both sides:
-x = 5
Divide both sides by -1:
x = -5
