Substituting the Slope and a Point

Oct 13, 2025 by wbrum.org 111 views

Introduction

In mathematics, the slope-intercept form of a line is a fundamental concept used to represent the equation of a line in a two-dimensional coordinate system. The slope-intercept form is given by the equation ${$ y = mx + b $}$, where ${$ m $}$ represents the slope of the line and ${$ b $}$ represents the y-intercept. In this article, we will explore how to find the value of ${$ b $}$ given two points on the line.

Understanding the Slope-Intercept Form

The slope-intercept form of a line is a powerful tool used to represent the equation of a line in a two-dimensional coordinate system. The equation is given by ${$ y = mx + b $}$, where ${$ m $}$ represents the slope of the line and ${$ b $}$ represents the y-intercept. The slope of a line is a measure of how steep the line is, and it is calculated as the ratio of the vertical change (rise) to the horizontal change (run) between two points on the line.

Calculating the Slope

To find the value of ${$ b $}$, we first need to calculate the slope of the line using the two given points. The slope of a line can be calculated using the formula ${$ m = \frac{y_2 - y_1}{x_2 - x_1} $}$, where ${$ (x_1, y_1) $}$ and ${$ (x_2, y_2) $}$ are the coordinates of the two points on the line.

Given Points

The two given points on the line are ${$ J(-4, -5) $}$ and ${$ K(-6, 3) $}$. We can use these points to calculate the slope of the line.

Calculating the Slope

To calculate the slope, we need to substitute the coordinates of the two points into the formula.

${$ m = \frac{y_2 - y_1}{x_2 - x_1} $}$

Substituting the coordinates of the two points, we get:

${$ m = \frac{3 - (-5)}{-6 - (-4)} $}$

Simplifying the expression, we get:

${$ m = \frac{8}{-2} $}$

${$ m = -4 $}$

Finding the Value of b

Now that we have the slope of the line, we can use it to find the value of ${$ b $}$. We can substitute the slope and one of the points into the equation ${$ y = mx + b $}$ to solve for ${$ b $}$.

Substituting the Slope and a Point

We can substitute the slope and the coordinates of point ${$ J(-4, -5) $}$ into the equation.

${$ -5 = (-4)(-4) + b $}$

Simplifying the expression, we get:

${$ -5 = 16 + b $}$

Subtracting 16 from both sides, we get:

${$ -21 = b $}$

Conclusion

In this article, we have explored how to find the value of ${$ b $}$ given two points on a line. We first calculated the slope of the line using the two given points, and then used the slope and one of the points to solve for ${$ b $}$. The value of ${$ b $}$ is a critical component of the slope-intercept form of a line, and it represents the y-intercept of the line. We hope that this article has provided a clear and concise explanation of how to find the value of ${$ b $}$ given two points on a line.

Additional Resources

For more information on the slope-intercept form of a line, we recommend checking out the following resources:

Khan Academy: Slope-Intercept Form
Mathway: Slope-Intercept Form
Wolfram Alpha: Slope-Intercept Form

Final Answer

Introduction

In our previous article, we explored how to find the value of ${$ b $}$ given two points on a line. We calculated the slope of the line using the two given points and then used the slope and one of the points to solve for ${$ b $}$. In this article, we will answer some frequently asked questions about finding the value of ${$ b $}$ in the slope-intercept form of a line.

Q&A

Q: What is the slope-intercept form of a line?

A: The slope-intercept form of a line is a fundamental concept used to represent the equation of a line in a two-dimensional coordinate system. The equation is given by ${$ y = mx + b $}$, where ${$ m $}$ represents the slope of the line and ${$ b $}$ represents the y-intercept.

Q: How do I calculate the slope of a line?

A: To calculate the slope of a line, you can use the formula ${$ m = \frac{y_2 - y_1}{x_2 - x_1} $}$, where ${$ (x_1, y_1) $}$ and ${$ (x_2, y_2) $}$ are the coordinates of the two points on the line.

Q: What is the y-intercept of a line?

A: The y-intercept of a line is the point where the line intersects the y-axis. It is represented by the value ${$ b $}$ in the slope-intercept form of a line.

Q: How do I find the value of b in the slope-intercept form of a line?

A: To find the value of ${$ b $}$, you can substitute the slope and one of the points into the equation ${$ y = mx + b $}$ and solve for ${$ b $}$.

Q: What if I have a horizontal line? How do I find the value of b?

A: If you have a horizontal line, the slope is zero, and the equation of the line is simply ${$ y = b $}$. In this case, the value of ${$ b $}$ is the y-coordinate of any point on the line.

Q: What if I have a vertical line? How do I find the value of b?

A: If you have a vertical line, the slope is undefined, and the equation of the line is simply ${$ x = b $}$. In this case, the value of ${$ b $}$ is the x-coordinate of any point on the line.

Q: Can I use the slope-intercept form of a line to find the equation of a line?

A: Yes, you can use the slope-intercept form of a line to find the equation of a line. Simply substitute the slope and the y-intercept into the equation ${$ y = mx + b $}$ and simplify.

Conclusion

In this article, we have answered some frequently asked questions about finding the value of ${$ b $}$ in the slope-intercept form of a line. We hope that this article has provided a clear and concise explanation of how to find the value of ${$ b $}$ given two points on a line.

Additional Resources

For more information on the slope-intercept form of a line, we recommend checking out the following resources:

Khan Academy: Slope-Intercept Form
Mathway: Slope-Intercept Form
Wolfram Alpha: Slope-Intercept Form

Final Answer

The final answer is: $\boxed{-21}$