What is x if 4^(4x-15)-4=0 ?

We'll re-write the equation, moving the coefficient -4 to
the right side:

4^(4x-15) =
4

We can write as
well:

4^(4x-15) = 4^1

Since
the bases are matching, we'll apply the one to one
rule:

4x-15 = 1

We'll add 15
both sides:

4x = 15 + 1

4x =
16

We'll divide by 4:

x =
4

The solution of the equation is x =
4.