A boat travels 100 km [N], then 40km [N], and finally 80 km[S]. The trip takes 6.5 hours

Displacement is the vector sum of all the three parts of the trip. On a sketch, it is the distance between the final point of the boat and its initial point, with the direction indicated.

The velocity is simply dividing displacement by time.

Thanks man but the only thing I'm stuck on is if the boat is 140 km [N] of the point of reference and its saying that the boat traveled 80 km [S] is that subtracting 80 from 140. Or d0 I have to go from +140 past the piont of reference all the way down to 80 km [S]

Make a little diagram. How would you get the distance from the final point to the starting point? :)

It's obviously (100 + 40 - 80)

Is that okay with you now? :)