It takes 4.5 hours for a ship moving downriver to get from port a to port b. the return journey takes 6.3 hours. the river flows at 40 meters per minute. what is the distance between the two ports? (give your answer in kilometers. 1 km = 1,000 meters)

The speed of the river is ...
.. (40 m/min)*(60 min/h)*((1 km)/(1000 m)) = 2.4 km/h

speed = distance/time
Let d represent the distance between the ports. Let s represent the speed of the ship.
Downstream, we have
.. s +2.4 = d/4.5
.. s = d/4.5 -2.4
Upstream, we have
.. s -2.4 = d/6/3
.. s = d/6.3 +2.4

Now, we have the speed of the ship represented two ways. We assume the speed of the ship doesn't vary. so these are equal.
.. (d/6.3) +2.4 = (d/4.5) -2.4
.. 4.8 = d(1/4.5 -1/6.3) = d(4/63) . . . . . rearrange and simplify
.. 75.6 = d . . . . . . . . . . . . . . . . . . . . . . .multiply by 63/4

The distance between the two ports is 75.6 km.

Iwould say false, not positive but if prices went up for both stores, technically there will be less buyers?

The answer to your question is b’(16,14)