Answer:
the 4th option
Explanation:
8 = 2³
so, when we convert

into a "2 to the power of" expression, we get therefore

and when we have an exponent of an exponent, we can simplify by multiplying these two exponents.
3×(x-3) = 3x - 9
and therefore we get

and by the way, we can now even easily solve this for x, as we know

after all, because 4x = x + x + x + x = 3x + x = ...
and because we got also

we know that 3x + x = 3x - 9
and that gives us x = -9