Answer:
x = 7 h
Step-by-step explanation:
First, we write the data of the problem.
Alex travels 810 miles away
Train - 90 miles / h
Alex covers 180 miles.
How many hours does Alex walk in the distance?
1. Calculate the distance Alex still has to travel.
810 miles - 180 miles = 630 miles
2. We take into account the speed of the train to calculate how many hours Alex will cover the remaining distance.
90 miles .... 1 h
630 miles .... x h
x = 630 milesx1h / 90 miles
x = 7 h