Plotting the First Equation

Oct 13, 2025 by wbrum.org 33 views

Introduction

In mathematics, a system of equations is a set of two or more equations that are solved simultaneously to find the values of the variables. There are several methods to solve a system of equations, including substitution, elimination, and graphing. In this article, we will focus on solving a system of equations by graphing.

What is Graphing?

Graphing is a method of solving a system of equations by plotting the equations on a coordinate plane and finding the point of intersection. This method is useful for solving systems of linear equations.

Step 1: Plot the Equations

To solve the system of equations by graphing, we need to plot the two equations on a coordinate plane. The first equation is y = 3 - x, and the second equation is y = (1/2)x - 3.

Plotting the First Equation

The first equation is y = 3 - x. To plot this equation, we can choose a value for x and calculate the corresponding value of y. For example, if x = 0, then y = 3 - 0 = 3. If x = 1, then y = 3 - 1 = 2. We can continue this process to plot several points on the graph.

Plotting the Second Equation

The second equation is y = (1/2)x - 3. To plot this equation, we can choose a value for x and calculate the corresponding value of y. For example, if x = 0, then y = (1/2)(0) - 3 = -3. If x = 1, then y = (1/2)(1) - 3 = -2.5. We can continue this process to plot several points on the graph.

Plotting the Graphs

Once we have plotted several points on each graph, we can draw a line through the points to represent the equation. The graph of the first equation is a straight line with a negative slope, and the graph of the second equation is a straight line with a positive slope.

Finding the Point of Intersection

To find the point of intersection, we need to find the point where the two lines intersect. This can be done by finding the x-coordinate of the point of intersection and then substituting this value into one of the equations to find the corresponding y-coordinate.

Finding the x-Coordinate of the Point of Intersection

To find the x-coordinate of the point of intersection, we can set the two equations equal to each other and solve for x. The two equations are y = 3 - x and y = (1/2)x - 3. We can set these equations equal to each other and solve for x:

3 - x = (1/2)x - 3

To solve for x, we can add x to both sides of the equation and then add 3 to both sides of the equation:

3 - x + x = (1/2)x - 3 + x

This simplifies to:

3 = (3/2)x - 3

To solve for x, we can add 3 to both sides of the equation and then divide both sides of the equation by (3/2):

3 + 3 = (3/2)x - 3 + 3

This simplifies to:

6 = (3/2)x

To solve for x, we can multiply both sides of the equation by 2/3:

(2/3)(6) = (3/2)x(2/3)

This simplifies to:

4 = x

Finding the y-Coordinate of the Point of Intersection

Now that we have found the x-coordinate of the point of intersection, we can substitute this value into one of the equations to find the corresponding y-coordinate. We will substitute x = 4 into the first equation:

y = 3 - x

y = 3 - 4

y = -1

Conclusion

In this article, we have solved a system of equations by graphing. We plotted the two equations on a coordinate plane and found the point of intersection. The point of intersection is the solution to the system of equations. We found that the x-coordinate of the point of intersection is 4 and the y-coordinate of the point of intersection is -1.

Answer

The answer to the system of equations is (4, -1).

Discussion

The system of equations has one solution, which is the point (4, -1). This means that the two lines intersect at this point, and the solution to the system of equations is the point of intersection.

Types of Solutions

There are three types of solutions to a system of equations:

One solution: The system of equations has one solution, which is the point of intersection.
No solution: The system of equations has no solution, which means that the two lines do not intersect.
Infinitely many solutions: The system of equations has infinitely many solutions, which means that the two lines are identical.

Conclusion

Q: What is the purpose of graphing in solving a system of equations?

A: The purpose of graphing in solving a system of equations is to visualize the equations and find the point of intersection, which is the solution to the system of equations.

Q: How do I plot the equations on a coordinate plane?

A: To plot the equations on a coordinate plane, you need to choose a value for x and calculate the corresponding value of y. You can use a table or a graphing calculator to help you plot the points.

Q: What is the difference between the two equations in the system of equations?

A: The two equations in the system of equations are y = 3 - x and y = (1/2)x - 3. The first equation is a straight line with a negative slope, and the second equation is a straight line with a positive slope.

Q: How do I find the point of intersection?

A: To find the point of intersection, you need to set the two equations equal to each other and solve for x. Then, you can substitute the value of x into one of the equations to find the corresponding value of y.

Q: What is the x-coordinate of the point of intersection?

A: The x-coordinate of the point of intersection is 4.

Q: What is the y-coordinate of the point of intersection?

A: The y-coordinate of the point of intersection is -1.

Q: What is the solution to the system of equations?

A: The solution to the system of equations is (4, -1).

Q: What type of solution does the system of equations have?

A: The system of equations has one solution, which is the point of intersection.

Q: What are the three types of solutions to a system of equations?

A: The three types of solutions to a system of equations are:

One solution: The system of equations has one solution, which is the point of intersection.
No solution: The system of equations has no solution, which means that the two lines do not intersect.
Infinitely many solutions: The system of equations has infinitely many solutions, which means that the two lines are identical.

Q: How do I determine the type of solution to a system of equations?

A: To determine the type of solution to a system of equations, you need to graph the equations and find the point of intersection. If the point of intersection is a single point, then the system of equations has one solution. If the point of intersection is not a single point, then the system of equations has no solution or infinitely many solutions.

Q: What are some common mistakes to avoid when solving a system of equations by graphing?

A: Some common mistakes to avoid when solving a system of equations by graphing include:

Plotting the equations incorrectly: Make sure to plot the equations correctly and accurately.
Finding the point of intersection incorrectly: Make sure to find the point of intersection correctly and accurately.
Determining the type of solution incorrectly: Make sure to determine the type of solution correctly and accurately.

Q: What are some real-world applications of solving a system of equations by graphing?

A: Some real-world applications of solving a system of equations by graphing include:

Physics: Solving a system of equations by graphing can be used to model the motion of objects in physics.
Engineering: Solving a system of equations by graphing can be used to design and optimize systems in engineering.
Economics: Solving a system of equations by graphing can be used to model economic systems and make predictions about economic trends.

Conclusion

In this article, we have answered some common questions about solving a system of equations by graphing. We have discussed the purpose of graphing, how to plot the equations, how to find the point of intersection, and how to determine the type of solution. We have also discussed some common mistakes to avoid and some real-world applications of solving a system of equations by graphing.