I would say 465 since they go back and forth twice which is 155 x 3
First, convert the distance of a typical marathon to kilometers.
1 mi = 1.609 km
26.2 miles = 42.165 km
Divide this distance by Allan's average speed to get his average time.
42.165 km / 12 km/hr = 3.514 hours
5+(x-5)=x
Simplify the left side by combining like terms:
5 + x - 5 = x
5-5 = 0
x = x
X = All real numbers.
