multiple attacks and expertise

[Kytess]

If a charascter has BAB +5, he/she can use Power Attack and Expertise for 5 each, ifthey so choose; with no other modifiers, they will atack at -5. There's no clause combining the limit, though you're unlikely to hit many creatures with an attack bonus of -5.

 

[Caliban]

Also remember that the penalty only lasts until your next action, not until your next turn.

This means that if you are hasted, you can make your normal attacks, then on your extra Partial Action use Expertise and gain the benefit until your next action, or you could use Power Attack on your normal action, then have it reset when on your extra Partial Action.