Solve for x: 9^4x - 27^x-4?

9^4x - 27^(x - 4) = 0

(3^2)^4x - (3^3)^(x - 4) = 0

3^(2*4x) - 3^[3(x - 4)] = 0

3^(8x) - 3^(3x - 12) = 0

3^(8x) = 3^(3x - 12)

8x = 3x - 12

5x = -12

x = -12/5

The word "solve" is applied to equations and equations require an = sign.

Yes