Answer :
38 km= (3x-1)+x+((3x-1)-2)
38 = 3x-1+x+3x-1-2
38 = 7x-4
7x=42
x=6 km --> second day
Test: 38 = (3*6-1)+6(3*6-1)-2)
--> frist day: 3*6-1 = 17 km
38 = 3x-1+x+3x-1-2
38 = 7x-4
7x=42
x=6 km --> second day
Test: 38 = (3*6-1)+6(3*6-1)-2)
--> frist day: 3*6-1 = 17 km