Question 834943
The question implies that the two planes are traveling the same route.


The jet, faster plane, flies for t hours.  Meanwhile, the one plane has been traveling for t+2 hours.  



_____________speed________time____________distance______|____Equations
slow plane______180__________t+2_____________d__________|__{{{180(t+2)=d}}}
Jet__________900___________t______________d__________|__{{{900t=d}}}


Pick either equation and solve for t.  Substitute the expression for t into the other equation and solve it for d.