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4 votes
The table below shows function d, which represents the distance of a car from its destination after driving for n hours.

Which function represents this situation?

d(n) = -60n + 690

d(n) = 65n - 690

d(n) = -65n + 690

d(n) = -690n + 65

The table below shows function d, which represents the distance of a car from its-example-1
User Mag Roader
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2 Answers

3 votes
Your answer is the first one because it starts at 690 and goes down by 65

User Zarjio
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4 votes
For this case, the first thing you should observe is that we have a linear equation.
The generic equation of the line in this case is:
d (n) - d (n0) = m (n-n0)
We look for the slope:
m = (d (n2) - d (n1)) / (n2-n1)
m = (560 - 690) / (2-0)
m = -65
Then, we choose any ordered pair:
(n0, d (n0)) = (0, 690)
We substitute the values in the generic equation:
d (n) - 690 = -65 (n-0)
We rewrite:
d (n) = -65n +690
Answer:
A function that represents this situation is:
d (n) = -65n +690
(option 3)
User RoelAdriaans
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