Consider the differential equation given by

$\displaystyle y'=ay-b^2y, a>0, b>0$

List the equilibrium solutions in increasing order and classify them as stable, semistable, or unstable.

I think I know to find the equilibrium solutions; you just factor out the y and get:

$\displaystyle y'=y(a-by)$

so the solutions are $\displaystyle y=0 , y=a/b$

But how to do I see whether they're stable, unstable, or semi stable?

any help is appreciated, thanks!