Question

Flock of birds is flying south, toward the equator, at an hourly rate. A scientist created the function f(x)=−60x+1320 to represent how many miles away from the equator the birds are after a given number of hours.

Which of the answers are true of the scenario represented by this function?

There is more than one correct answer. Select all answers that apply.

The birds began 1320 miles from the equator.
It will take the birds 1320 hours to reach the equator.
The birds began 60 miles from the equator.
It takes the birds 60 hours to fly x miles.
The birds are flying toward the equator at a rate of 1320 mph.
The birds are flying toward the equator at a rate of 60 mph.

Answer 1

The birds began 1320 miles from the equator.

The birds are flying toward the equator at a rate of 60 mph.

Explanation:

Answer 2

Answer: First and last option

The birds began 1320 miles from the equator.

The birds are flying toward the equator at a rate of 60 mph.

Explanation:

Note that the function f(x) is a linear function.

`f (x) = - 60x + 1320`

If x represents the number of hours and f(x) represents the distance from the equator, then x = 0 means that the first hour has not yet elapsed.

When x = 0 then:

`f (0) = -60 * 0 +1320\\f (0) = 1320`.

This means that the initial distance at which the birds of the equator are located is 1320 miles.

Then when x = 1 then:

`f (x) = -60 * 1 + 1320\\f (x) = -60 +1320`

When x = 2 then:

`f (x) = -60 * 2 + 1320\\f (x) = -120 +1320`

As x increases by one unit then the distance of the birds to the equator decreases by 60 miles. This means that birds travel at a speed of 60 miles per hour