Question 831176
r, speed of the propeller plane


_____________speed____________time____________distance
Jet__________r+80_____________h-2_______________3960
Propeller____r_________________h________________3960



R*t=d the uniform rates equation for travel, R meaning rate, t for time, d for distance.


JET:  {{{(r+80)(h-2)=3960}}};
PROP:  {{{rh=3960}}}.


I solved the same general question a couple days ago, just a slightly different example.  The equations were similar.  Try understanding this problem description and solving the system yourself.  


Look-up problem number 830872
http://www.algebra.com/algebra/homework/word/travel/Travel_Word_Problems.faq.question.830872.html