It is 6 because 1000 would not be the appropiate answer
If you draw out a coordinate plane you will see that they , on their Y access, are both nine witch means that they a horizontal line so all you have to do is subtract the x access witch is 3.
hope this helped
Average rate= change in alt / change in time
r=-378/7=-54ft/min
The last one y=2x-5 if you plug the points into the x and y values you can see this equation works for both points.
