Too many questions for a single thread. In the future no more than three.

y = 1/4 is not a typical function to graph. Is there an x missing in here somewhere?

500 = 5 x 10^2. So log(500) = ?

To get an inverse you switch x and y. So if you have then you needs to solve for y. How do you get the y - 1 out of the exponent?

Try that out for now.

-Dan