Using a Table of Values to Write an Equation

Oct 13, 2025 by wbrum.org 50 views

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Introduction

Linear functions are a fundamental concept in mathematics, and writing equations of linear functions is a crucial skill for students to master. In this article, we will explore the process of writing equations of linear functions in slope-intercept form, using a given table of values.

Understanding Slope-Intercept Form

The slope-intercept form of a linear function is given by the equation:

y = mx + b

where m is the slope of the line, and b is the y-intercept. The slope-intercept form is a convenient way to represent linear functions, as it allows us to easily identify the slope and y-intercept of the line.

Using a Table of Values to Write an Equation

Let's consider the following table of values:

P	A	H	S	L	E
-9	-8	3	1	8	4
O	C	K	D
5	9	-4

In this table, we have six values for the variables P, A, H, S, L, and E. We can use these values to write an equation in slope-intercept form.

Finding the Slope

To find the slope of the line, we need to calculate the ratio of the change in y to the change in x. Let's consider the two points (-9, -8) and (5, 9).

The change in y is 9 - (-8) = 17

The change in x is 5 - (-9) = 14

The slope is given by the ratio of the change in y to the change in x:

m = 17/14 ≈ 1.21

Finding the Y-Intercept

Now that we have the slope, we can use one of the points to find the y-intercept. Let's use the point (-9, -8).

We can substitute the values of x and y into the equation y = mx + b:

-8 = 1.21(-9) + b

Simplifying the equation, we get:

-8 = -10.89 + b

Adding 10.89 to both sides, we get:

b = 2.89

Writing the Equation

Now that we have the slope and y-intercept, we can write the equation in slope-intercept form:

y = 1.21x + 2.89

Conclusion

Example Problems

Problem 1

Write an equation in slope-intercept form using the following table of values:

x	y
2	3
4	5
6	7

Solution

To find the slope, we need to calculate the ratio of the change in y to the change in x. Let's consider the two points (2, 3) and (4, 5).

The change in y is 5 - 3 = 2

The change in x is 4 - 2 = 2

The slope is given by the ratio of the change in y to the change in x:

m = 2/2 = 1

Now that we have the slope, we can use one of the points to find the y-intercept. Let's use the point (2, 3).

We can substitute the values of x and y into the equation y = mx + b:

3 = 1(2) + b

Simplifying the equation, we get:

3 = 2 + b

Subtracting 2 from both sides, we get:

b = 1

Now that we have the slope and y-intercept, we can write the equation in slope-intercept form:

y = x + 1

Problem 2

Write an equation in slope-intercept form using the following table of values:

x	y
-2	4
0	2
2	0

Solution

To find the slope, we need to calculate the ratio of the change in y to the change in x. Let's consider the two points (-2, 4) and (0, 2).

The change in y is 2 - 4 = -2

The change in x is 0 - (-2) = 2

The slope is given by the ratio of the change in y to the change in x:

m = -2/2 = -1

Now that we have the slope, we can use one of the points to find the y-intercept. Let's use the point (0, 2).

We can substitute the values of x and y into the equation y = mx + b:

2 = -1(0) + b

Simplifying the equation, we get:

2 = b

Now that we have the slope and y-intercept, we can write the equation in slope-intercept form:

y = -x + 2

Tips and Tricks

When writing an equation in slope-intercept form, make sure to use the correct slope and y-intercept.
Use a table of values to help you find the slope and y-intercept.
Check your work by plugging in the values of x and y into the equation to make sure it is true.

Common Mistakes

Forgetting to use the correct slope and y-intercept.
Not using a table of values to help find the slope and y-intercept.
Not checking your work by plugging in the values of x and y into the equation.

Conclusion

In this article, we have seen how to write an equation of a linear function in slope-intercept form using a table of values. We have also seen how to find the slope and y-intercept of the line, and how to use these values to write the equation. By following the steps outlined in this article, you should be able to write equations of linear functions with ease.

Introduction

In our previous article, we explored the process of writing equations of linear functions in slope-intercept form using a table of values. In this article, we will answer some frequently asked questions about writing equations of linear functions.

Q&A

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

A: The slope-intercept form of a linear function is given by the equation y = mx + b, where m is the slope of the line and b is the y-intercept.

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

A: To find the slope of a line, you need to calculate the ratio of the change in y to the change in x. You can use the formula m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are two points on the line.

Q: How do I find the y-intercept of a line?

A: To find the y-intercept of a line, you need to use one of the points on the line and the slope of the line. You can use the formula b = y - mx, where m is the slope and (x, y) is a point on the line.

Q: What is the difference between the slope and the y-intercept?

A: The slope of a line is a measure of how steep the line is, while the y-intercept is the point where the line intersects the y-axis.

Q: How do I write an equation of a linear function in slope-intercept form?

A: To write an equation of a linear function in slope-intercept form, you need to find the slope and y-intercept of the line. You can use the formula y = mx + b, where m is the slope and b is the y-intercept.

Q: What are some common mistakes to avoid when writing equations of linear functions?

A: Some common mistakes to avoid when writing equations of linear functions include forgetting to use the correct slope and y-intercept, not using a table of values to help find the slope and y-intercept, and not checking your work by plugging in the values of x and y into the equation.

Q: How do I check my work when writing an equation of a linear function?

A: To check your work when writing an equation of a linear function, you need to plug in the values of x and y into the equation to make sure it is true. You can use a table of values to help you do this.

Q: What are some real-world applications of writing equations of linear functions?

A: Writing equations of linear functions has many real-world applications, including modeling population growth, predicting stock prices, and calculating the cost of goods.

Conclusion

In this article, we have answered some frequently asked questions about writing equations of linear functions. We have also provided some tips and tricks for writing equations of linear functions, as well as some common mistakes to avoid. By following the steps outlined in this article, you should be able to write equations of linear functions with ease.

Example Problems

Problem 1

Write an equation in slope-intercept form using the following table of values:

x	y
2	3
4	5
6	7

Solution

To find the slope, we need to calculate the ratio of the change in y to the change in x. Let's consider the two points (2, 3) and (4, 5).

The change in y is 5 - 3 = 2

The change in x is 4 - 2 = 2

The slope is given by the ratio of the change in y to the change in x:

m = 2/2 = 1

Now that we have the slope, we can use one of the points to find the y-intercept. Let's use the point (2, 3).

We can substitute the values of x and y into the equation y = mx + b:

3 = 1(2) + b

Simplifying the equation, we get:

3 = 2 + b

Subtracting 2 from both sides, we get:

b = 1

Now that we have the slope and y-intercept, we can write the equation in slope-intercept form:

y = x + 1

Problem 2

Write an equation in slope-intercept form using the following table of values:

x	y
-2	4
0	2
2	0

Solution

To find the slope, we need to calculate the ratio of the change in y to the change in x. Let's consider the two points (-2, 4) and (0, 2).

The change in y is 2 - 4 = -2

The change in x is 0 - (-2) = 2

The slope is given by the ratio of the change in y to the change in x:

m = -2/2 = -1

Now that we have the slope, we can use one of the points to find the y-intercept. Let's use the point (0, 2).

We can substitute the values of x and y into the equation y = mx + b:

2 = -1(0) + b

Simplifying the equation, we get:

2 = b

Now that we have the slope and y-intercept, we can write the equation in slope-intercept form:

y = -x + 2

Tips and Tricks

When writing an equation in slope-intercept form, make sure to use the correct slope and y-intercept.
Use a table of values to help you find the slope and y-intercept.
Check your work by plugging in the values of x and y into the equation to make sure it is true.

Common Mistakes

Forgetting to use the correct slope and y-intercept.
Not using a table of values to help find the slope and y-intercept.
Not checking your work by plugging in the values of x and y into the equation.