Answer:
Friend 1 = 3 mph
Friend 2 = 4 mph
Step-by-step explanation:
We know the total distance is 7 miles. We know that 7 miles is the sum of Friend 1 plus Friend 2. So
D = D(F1) + D(F2) = 7
and we also know that Friend 2 walked 1 more mile than Friend 1 so
D + (D + 1) = 7
2D + 1 = 7
2D = 6
D = 3 miles for Friend 1 and 3 + 1 = 4 miles for Friend 2.
Speed is distance/Time so
S(F1) = 3 miles/1 hour
and
S(F2) = 4 miles/1 hour
