x: -12, -9, -6, -3, 0

y:1, -3, -7, -11, -15
Table
What is the slope of the line that goes through the points in the table?
What's the equation of the line that goes through all of the points in the table in slope-intercept form?

1 answer

To find the slope \( m \) of the line that goes through the points given in the table, we can use any two points from the dataset. Let's take the first two points:

  • Point 1: \((-12, 1)\)
  • Point 2: \((-9, -3)\)

The formula for the slope \( m \) between two points \((x_1, y_1)\) and \((x_2, y_2)\) is:

\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]

Substituting the coordinates of our points:

\[ m = \frac{-3 - 1}{-9 - (-12)} = \frac{-4}{-9 + 12} = \frac{-4}{3} \]

Thus, the slope \( m \) is \(-\frac{4}{3}\).

Next, we need to find the equation of the line in slope-intercept form, which is given by:

\[ y = mx + b \]

Where \( m \) is the slope and \( b \) is the y-intercept. We already found that \( m = -\frac{4}{3} \). To find \( b \), we can use one of the points. Let's use the point \((-12, 1)\):

\[ 1 = -\frac{4}{3}(-12) + b \]

Calculating the right side:

\[ 1 = \frac{48}{3} + b \] \[ 1 = 16 + b \]

Now, we solve for \( b \):

\[ b = 1 - 16 = -15 \]

So, the y-intercept \( b \) is \(-15\).

Now we can write the equation of the line in slope-intercept form:

\[ y = -\frac{4}{3}x - 15 \]

In summary:

  • The slope of the line is \(-\frac{4}{3}\).
  • The equation of the line in slope-intercept form is \( y = -\frac{4}{3}x - 15 \).