Answer:
The ship traveled 120 miles in 4.8 hours.
The submarine traveled 75 miles in 5 hours.
Step-by-step explanation:
In this case, we just have to use the given graph to answer correctly the submarine voyage. In addition, the given function relates Hours with Distance (miles) about a ship voyage. First, the problem is asking about the time when it traveled 120 miles, and it's asking the distance after traveling 5 hours, to answer that question we just have to see what values belong to each question.
So, the expression [tex]f(x) = 120 - 25x[/tex] specify that the ship is starting from 120 miles away the objective, because when x = 0 (the initial point), y = f(x) = 120. This means that after traveling 120 miles, the ship will be 0 miles away, so f(x) = 0. Replacing this value we will find the needed time to travel 120 miles.
[tex]f(x) = 120 - 25x[/tex]
[tex]0= 120 - 25x[/tex]
[tex]25x= 120[/tex]
[tex]x=\frac{120}{25}=4.8[/tex]
Therefore, it will require 4.8 hours to travel 120 miles.
The second question is asking miles traveled after 5 hours by the submarine. In this case, the graph belongs to the submarine. We observe that in x = 5 hours, the distance traveled is 75 miles, because the line dropped from 75 to 0 miles, when went horizontally from 0 to 5 hours, meaning that after 5 hours, it traveled 75 miles.