Answer:
first stage=420km
second stage=360Km
Explanation:
 
Hi! 
To solve the problem follow the steps below 
1. We will call X to the first stage and Y to the second stage. 
2. Raise the equations taking into account the following 
 
the sum of both stages is 780km 
 
X+Y=780km
the first stage has 60km more than the second
Y+60=X
X-Y=60
 
3. Add the equations found above
X + Y =780
X - Y =60 
------------------------
2X=840
Solving for X=840/2=420Km
 
use one of the equations obtained in step 2, to get the value of Y
Y+60=X
X-60=Y
420-60=Y
Y=360km