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 answer

To determine the correct equation that describes the function represented by the table, we can first analyze the given points:

\[ \begin{align*} (0, -5) \ (1, -9) \ (2, -13) \ (3, -17) \ \end{align*} \]

We can observe that as \( x \) increases, \( y \) decreases.

To find a linear equation of the form \( y = mx + b \), we need to determine the slope \( m \) and the y-intercept \( b \).

  1. Calculate the slope \( m \): Using two points, for example, \( (0, -5) \) and \( (1, -9) \):

    \[ m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{-9 - (-5)}{1 - 0} = \frac{-9 + 5}{1} = \frac{-4}{1} = -4 \]

  2. Find the y-intercept \( b \): We can use the y-value when \( x = 0 \) (which is -5) in the equation \( y = mx + b \): \[ -5 = -4(0) + b \ b = -5 \]

Now we have both \( m \) and \( b \). The equation of the function is:

\[ y = -4x - 5 \]

Using function notation, we write:

\[ f(x) = -4x - 5 \]

Thus, the correct equation that describes the function in the table is:

\[ f(x) = -4x - 5 \]