Question 334347
Write an expression for the number of kilometers a dolphin travels in d hours of swimming at 8km/h? 
.
The expression is simply "speed" times "time" or
8d
.
goes on to ask in part two the number of kilometers the dolphin travels in three hours. 
In three hours;
d = 3
substitute into:
8d
to get
8(3) = 24 km