The variable "x" equals 7
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
31 quarts, because there are 4 quarts in a gallon
3-5w+12+2w-3
(3+12-3)=12
(-5w+2w)=-3w
-3w+12