Answer:
After Andrew hiked the three trails, he was 3.8 miles away from his house.
Explanation:
The calculation is the following:
4.5 miles of the first hike minus 2.4 miles of the second hike
4.5-2.4= 2.1
Then you have to add to those 2.1 miles the 1.7 miles of the third and last hike
2.1+1.7= 3.8 miles