Use The Substitution Method To Solve The System Of Equations Shown.$ \begin{align*} x + Y &= 6 \\ x &= 3y - 2 \end{align*} $A. (4, 2) B. (1, 5) C. (-2, 8) D. None Of These

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Introduction

Systems of equations are a fundamental concept in mathematics, and solving them is a crucial skill for students to master. In this article, we will explore the substitution method, a powerful technique for solving systems of equations. We will use a step-by-step approach to solve a system of linear equations, and provide a clear explanation of the process.

What is the Substitution Method?

The substitution method is a technique used to solve systems of equations by substituting one equation into another. This method is particularly useful when one of the equations can be easily solved for one of the variables. The substitution method involves the following steps:

  1. Solve one of the equations for one of the variables: This can be done by isolating the variable on one side of the equation.
  2. Substitute the expression for the variable into the other equation: This will result in a new equation with only one variable.
  3. Solve the resulting equation for the remaining variable: This will give us the value of the variable.
  4. Substitute the value of the variable back into one of the original equations: This will allow us to find the value of the other variable.

Step-by-Step Solution

Let's use the substitution method to solve the system of equations:

\begin{align*} x + y &= 6 \ x &= 3y - 2 \end{align*}

Step 1: Solve one of the equations for one of the variables

We can solve the second equation for x:

x=3y−2x = 3y - 2

Step 2: Substitute the expression for the variable into the other equation

We can substitute the expression for x into the first equation:

(3y−2)+y=6(3y - 2) + y = 6

Step 3: Solve the resulting equation for the remaining variable

We can simplify the equation by combining like terms:

4y−2=64y - 2 = 6

Adding 2 to both sides of the equation gives us:

4y=84y = 8

Dividing both sides of the equation by 4 gives us:

y=2y = 2

Step 4: Substitute the value of the variable back into one of the original equations

We can substitute the value of y back into the second equation:

x=3(2)−2x = 3(2) - 2

Simplifying the equation gives us:

x=6−2x = 6 - 2

x=4x = 4

Conclusion

We have successfully used the substitution method to solve the system of equations. The solution is x = 4 and y = 2.

Answer

The correct answer is A. (4, 2).

Discussion

The substitution method is a powerful technique for solving systems of equations. By following the steps outlined above, we can easily solve systems of linear equations. This method is particularly useful when one of the equations can be easily solved for one of the variables.

Example Problems

Here are a few example problems to try:

  1. Solve the system of equations using the substitution method:

\begin{align*} x + y &= 4 \ x &= 2y - 3 \end{align*}

  1. Solve the system of equations using the substitution method:

\begin{align*} x - y &= 2 \ x &= 3y + 1 \end{align*}

Tips and Tricks

Here are a few tips and tricks to keep in mind when using the substitution method:

  • Make sure to solve one of the equations for one of the variables before substituting it into the other equation.
  • Be careful when simplifying the resulting equation.
  • Make sure to substitute the value of the variable back into one of the original equations to find the value of the other variable.

Conclusion

Q: What is the substitution method?

A: The substitution method is a technique used to solve systems of equations by substituting one equation into another. This method is particularly useful when one of the equations can be easily solved for one of the variables.

Q: How do I know which equation to solve for the variable?

A: You can choose either equation to solve for the variable, but it's often easier to solve the equation that has the variable isolated on one side.

Q: What if I get stuck during the substitution process?

A: Don't worry! If you get stuck, try going back to the previous step and re-evaluating your work. You can also try using a different method, such as the elimination method, to solve the system of equations.

Q: Can I use the substitution method to solve systems of nonlinear equations?

A: No, the substitution method is typically used to solve systems of linear equations. Nonlinear equations require different techniques, such as the quadratic formula or numerical methods.

Q: How do I know if the substitution method is the best method to use?

A: If one of the equations can be easily solved for one of the variables, the substitution method is often the best choice. However, if the equations are complex or have multiple variables, other methods, such as the elimination method or graphing, may be more effective.

Q: Can I use the substitution method to solve systems of equations with more than two variables?

A: Yes, the substitution method can be used to solve systems of equations with more than two variables. However, it may become more complicated and require more steps.

Q: What are some common mistakes to avoid when using the substitution method?

A: Some common mistakes to avoid include:

  • Not solving one of the equations for the variable before substituting it into the other equation
  • Not simplifying the resulting equation correctly
  • Not substituting the value of the variable back into one of the original equations to find the value of the other variable

Q: How can I practice using the substitution method?

A: You can practice using the substitution method by working through example problems, such as those found in this article. You can also try creating your own systems of equations and using the substitution method to solve them.

Q: What are some real-world applications of the substitution method?

A: The substitution method has many real-world applications, including:

  • Solving systems of equations in physics and engineering
  • Modeling population growth and decline
  • Analyzing financial data and making predictions
  • Solving systems of equations in computer science and programming

Conclusion

In conclusion, the substitution method is a powerful technique for solving systems of equations. By following the steps outlined in this article and practicing with example problems, you can become proficient in using the substitution method to solve systems of equations. Remember to avoid common mistakes and to use the substitution method when one of the equations can be easily solved for one of the variables.