I want maple 15 to show me how it works out the formula (transposition) from N = 40^(1.5t) to t = 0.666..7(ln(1/40)*N)

I want to know how it transposes this formula from N to t I want the steps the actual working, I can't seem to figure it out as I'm using maple 15 as a learning tool, I have all the student modules installed but have no idea what I'm doing here

> N = 40*exp(1.5*t);
                       N = 40 exp(1.5 t)