Find the inverse of

f(x) = log(2+x) - 4
the base is "a"

Call f(x) y
y = loga(2+x) -4
y+4 = loga(2+x)
a^(y+4) = 2 + x
x = a^(y+4) - 2

drwls, you have merely solved the equation for x.
The question was to find the "inverse", so the actual answer should be

y = a^(x+4) - 2