exponential equation transformation....

Hi,

I have the following problem that I am stuck on. I know it is probably something basic that I am missing and I would appreciate any and all help.

Thanks,

TC

Write 2 different exponential equations with different bases if there is a y intercept of 5 and an asymptote at y=3.

I have gotten this far....

y = a^x + 4

a is the base, I know that anything to the power of 0 equals 1 so this equation satisfies the y-intercept part but I am at a loss about finding some way to have an asymptote at y=3