keep (one's) end of the bargain up

To do as one promised in an agreement or bargain; to carry through with what one agreed to do. OK, I've delivered the cash as you instructed. Now you have to keep your end of the bargain up! We've done the work on our end. I just hope their team keeps their end of the bargain up! My dad said he'd buy me a car if I got a 4.0 this semester, so I've got to ace this test if I want to keep my end of the bargain up.