Question

A student is running a 10-kilometer race. He runs 1 kilometer every 4 minutes. Select the function that describes his distance from the finish line after x minutes.

f(x) = 1 over 4x + 4

f(x) = − 1 over 10x + 4

f(x) = 1 over 10x + 10

f(x) = − 1 over 4x + 10

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I thought it was c but I was wrong. Could anybody help?

Answer 1

The function that describes the student's distance from the finish line after x minutes is f(x) = 1/(10x + 10).

Step-by-step explanation:

The function that describes the student's distance from the finish line after x minutes is f(x) = 1/(10x + 10).

To understand why, let's break it down step by step:

1. The student runs 1 kilometer every 4 minutes.

2. We can write this as a rate: 1 kilometer/4 minutes

3. The student runs for x minutes, so the distance covered is x * (1 kilometer/4 minutes)

4. Simplifying, we get f(x) = x/4 kilometers

5. However, the question asks for the distance from the finish line, not the starting line. The student has already run 10 kilometers, so we need to subtract this from the total distance. Therefore, the function becomes f(x) = x/4 - 10

6. Finally, we can simplify further to get f(x) = 1/(10x + 10).

Answer 2

What does 'over' denotes