Locating astronomical objects with reference to equatorial coordinate system on the celestial sphere is called spherical astronomy. It is one of the oldest observational astronomical branch which uses various mathematical concepts specifically, geometry calculation for measurement estimation. It can also be referred as positional astronomy generally envelops entire earth geometry to analysis.
Basically, it includes different parameters of earth's geometry along with its equator in line to celestial objects which finally gives location of these objects in particular year. All in all, it is a specialized science field in astronomy which first observes around space envelope and finally gives data about location of individual space objects with respect to tome.

Both of the functions are linear.
is constant.
However we are required to determine the range of 

So the only possible solution that such notation gives is -2374 so therefore the answer in terms of range is 
Hope this helps.
r3t40
You just divide the distance travelled by the time like so: 145mi/2.5h and get 58mph. You can convert the 145mi into meters and 2.5h into seconds (145mi is approximately 233345m; 2.5h is 9000 seconds) and get an approximate speed of 26m/s if you want to convert to SI units.