Re-write 25 = 5^{2}, and re-write 125 = 5^{3}

The above two revisions result in this equation**:**

[5^{2}]^{3x+6} = [5^{3}]^{12 - 2x}

and using Rules for exponents?

5^{2(3x+6)} = 5^{3(12 - 2x)}

If the powers are equal, and the bases (here, 2) are equal
then the exponents must also be equal**:**

2(3x + 6) = 3(12 - 2x)

6x + 12 = 36 - 6x

12x = 24

x = 2 |