Use the table to answer the question.

x y
0 −5
1 −9
2 −13
3 −17
Which of the following equations correctly describes the function in the table using function notation?



(1 point)
Responses

f(x)=−5x−4

f of x is equal to negative 5 x minus 4

f(x)=−4x−5
f left parenthesis x right parenthesis equals negative 4 x minus 5

f(y)=−4x−5
f left parenthesis y right parenthesis equals negative 4 x minus 5

f(y)=−5x−4

1 answer

To find the correct function that describes the relationship in the table, we first need to identify the pattern.

The values in the table are:

\[ \begin{array}{|c|c|} \hline x & y \ \hline 0 & -5 \ 1 & -9 \ 2 & -13 \ 3 & -17 \ \hline \end{array} \]

Let's look at the change in \(y\) values as \(x\) increases:

  • From \(x=0\) to \(x=1\): \(y\) changes from \(-5\) to \(-9\) (change of \(-4\))
  • From \(x=1\) to \(x=2\): \(y\) changes from \(-9\) to \(-13\) (change of \(-4\))
  • From \(x=2\) to \(x=3\): \(y\) changes from \(-13\) to \(-17\) (change of \(-4\))

The \(y\) value decreases by 4 for each increase of 1 in \(x\). This suggests a linear function with a slope of -4.

Now, let's find the equation in the form \(y = mx + b\):

  1. The slope (\(m\)) is -4.
  2. We can use one of the points to find \(b\). Using the point \(x = 0, y = -5\): \[ -5 = -4(0) + b \implies b = -5 \]

So, the equation is: \[ y = -4x - 5 \]

In function notation, this is: \[ f(x) = -4x - 5 \]

Now let's review the answer choices:

  1. \(f(x) = -5x - 4\) (incorrect)
  2. \(f(x) = -4x - 5\) (correct)
  3. \(f(y) = -4x - 5\) (incorrect - should be \(f(x)\))
  4. \(f(y) = -5x - 4\) (incorrect - should be \(f(x)\))

Therefore, the correct response is:

f(x) = -4x - 5.