Answer:


Explanation:
Notation and info given
Let's define some notation first:
represent the speed for the Private's jet
represent the speed for the Commercial jet
represent the total distance traveled (variable of interest)
represent the time to travel a distance x for the commercial jet
represent the time to travel a distance x for the private's jet
Solution to the problem
Since both jets are travelling the same distance we can set up the following equation:
Form the definition of distance we know that
and if we replace this we got this:


We know that also: "If the speed of the commercial jet was 57 mph less than 2 times the speed of the private jet", so then we have this expresion:

And if we replace this condition we got this:

And we can find
solving the equation like this:


And now we can replace in order to find
like this:
