Ok, I'm Assuming the wts you gave are the truck with the trailer connected and those are the front truck axle, rear truck axle and both trailer axles combined?
To completely figure out your wts, you need to go and have the truck weighed without the trailer.
Once you get the rear axle wt of the truck without the trailer, then subtract that from the first wt of the rear truck axle (with trailer) and that will give you the Pin wt of the trailer.
Then you can add the trailer Pin wt and the trailer (combined) axle wt you got on the first weigh, and that is the trailer total wt.
Easy eh??
Cheers,
Bill