Questions: Now, find the equation in terms of x for a line that passes through the two points (-1,3) and (4,-5). Express your answer in terms of x. The " y= " has been given for you.
Transcript text: Now, find the equation in terms of $x$ for a line that passes through the two points $(-1,3)$ and $(4,-5)$. Express your answer in terms of $x$. The " $y=$ " has been given for you.
Solution
Solution Steps
To find the equation of a line that passes through two given points, we need to determine the slope of the line and then use the point-slope form of the equation of a line. The slope \( m \) is calculated as the change in \( y \) divided by the change in \( x \). Once we have the slope, we can use one of the points to find the y-intercept \( b \) using the equation \( y = mx + b \).
Solution Approach
Calculate the slope \( m \) using the formula \( m = \frac{y_2 - y_1}{x_2 - x_1} \).
Use the slope and one of the points to solve for the y-intercept \( b \) using the equation \( y = mx + b \).
Write the final equation in the form \( y = mx + b \).
Step 1: Calculate the Slope
To find the equation of the line passing through the points \((-1, 3)\) and \( (4, -5) \), we first calculate the slope \( m \). The slope is given by:
\[
m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{-5 - 3}{4 - (-1)} = \frac{-8}{5} = -1.6
\]
Step 2: Calculate the Y-Intercept
Next, we use the slope \( m \) and one of the points to find the y-intercept \( b \). Using the point \((-1, 3)\):
\[
y = mx + b \implies 3 = -1.6(-1) + b \implies 3 = 1.6 + b \implies b = 3 - 1.6 = 1.4
\]