Questions: A line passes through the points (-6,-9) and (5,-9). Write its equation in slope-intercept form.
Transcript text: A line passes through the points $(-6,-9)$ and $(5,-9)$. Write its equation in slope-intercept form.
Write your answer using integers, proper fractions, and improper fractions in simplest form.
Solution
Solution Steps
Step 1: Calculate the slope of the line
The slope \( m \) of a line passing through two points \( (x_1, y_1) \) and \( (x_2, y_2) \) is given by:
\[
m = \frac{y_2 - y_1}{x_2 - x_1}
\]
Substitute the given points \( (-6, -9) \) and \( (5, -9) \):
\[
m = \frac{-9 - (-9)}{5 - (-6)} = \frac{0}{11} = 0
\]
Step 2: Determine the y-intercept
Since the slope \( m = 0 \), the line is horizontal. The equation of a horizontal line is:
\[
y = b
\]
where \( b \) is the y-coordinate of any point on the line. Using the point \( (-6, -9) \):
\[
y = -9
\]
Step 3: Write the equation in slope-intercept form
The slope-intercept form of a line is:
\[
y = mx + b
\]
Substitute \( m = 0 \) and \( b = -9 \):
\[
y = 0x - 9
\]
Simplify:
\[
y = -9
\]