Final answer:
The distance of the boat from the marina after t hours is given by the equation D = 100 km - (10 km/h × t). This represents a linear relationship, with D decreasing as time increases.
Step-by-step explanation:
To find the equation for the distance of the boat from the marina after t hours, we start with the initial distance and subtract the distance traveled by the boat over time. The boat starts 100 kilometers away and travels at a rate of 10 kilometers per hour towards the marina.
The distance traveled by the boat after t hours is simply the speed of the boat multiplied by the time, which is 10 km/h × t hours. Therefore, to find the remaining distance to the marina after t hours, we subtract the distance traveled from the initial distance:
This equation represents a linear relationship between the time t and the distance D from the marina.