Check if the equations are linear

Oct 13, 2025 by wbrum.org 27 views

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Introduction

Solving a system of equations is a fundamental concept in mathematics that involves finding the values of variables that satisfy multiple equations simultaneously. In this article, we will focus on solving a system of two equations with two variables, x and y. The system consists of a quadratic equation and a linear equation, which can be solved using algebraic methods.

The System of Equations

The given system of equations is:

{ \begin{cases} y = 2x^2 + x \\ 2x + y = 20 \end{cases} \}

Our goal is to find the values of x and y that satisfy both equations simultaneously.

Step 1: Substitute the Expression for y into the Second Equation

We can start by substituting the expression for y from the first equation into the second equation. This will give us an equation with only one variable, x.

{ 2x + (2x^2 + x) = 20 \}

Step 2: Simplify the Equation

Next, we can simplify the equation by combining like terms.

{ 2x + 2x^2 + x = 20 \}

{ 2x^2 + 3x - 20 = 0 \}

Step 3: Solve the Quadratic Equation

Now, we have a quadratic equation in the form of ax^2 + bx + c = 0, where a = 2, b = 3, and c = -20. We can solve this equation using the quadratic formula:

{ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \}

Plugging in the values of a, b, and c, we get:

{ x = \frac{-3 \pm \sqrt{3^2 - 4(2)(-20)}}{2(2)} \}

{ x = \frac{-3 \pm \sqrt{9 + 160}}{4} \}

{ x = \frac{-3 \pm \sqrt{169}}{4} \}

{ x = \frac{-3 \pm 13}{4} \}

Step 4: Find the Values of x

Now, we have two possible values for x:

{ x_1 = \frac{-3 + 13}{4} = \frac{10}{4} = 2.5 \}

{ x_2 = \frac{-3 - 13}{4} = \frac{-16}{4} = -4 \}

Step 5: Find the Corresponding Values of y

Now that we have the values of x, we can substitute them into one of the original equations to find the corresponding values of y.

For x = 2.5, we get:

{ y = 2(2.5)^2 + 2.5 \}

{ y = 2(6.25) + 2.5 \}

{ y = 12.5 + 2.5 \}

{ y = 15 \}

For x = -4, we get:

{ y = 2(-4)^2 + (-4) \}

{ y = 2(16) - 4 \}

{ y = 32 - 4 \}

{ y = 28 \}

Conclusion

In this article, we solved a system of two equations with two variables, x and y. We used algebraic methods to find the values of x and y that satisfy both equations simultaneously. The system consisted of a quadratic equation and a linear equation, which can be solved using the quadratic formula. We found two possible values for x and the corresponding values of y. The final answer is:

x = 2.5, y = 15
x = -4, y = 28

Final Answer

The final answer is $\boxed{2.5, 15}$ and $\boxed{-4, 28}$ .

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Introduction

In our previous article, we solved a system of two equations with two variables, x and y. We used algebraic methods to find the values of x and y that satisfy both equations simultaneously. In this article, we will provide a Q&A guide to help you understand the concepts and methods used in solving systems of equations.

Q: What is a system of equations?

A: A system of equations is a set of two or more equations that involve two or more variables. In this article, we will focus on solving a system of two equations with two variables, x and y.

Q: What are the different types of systems of equations?

A: There are two main types of systems of equations:

Linear systems: These are systems of equations where each equation is linear, meaning it can be written in the form ax + by = c, where a, b, and c are constants.
Nonlinear systems: These are systems of equations where at least one equation is nonlinear, meaning it cannot be written in the form ax + by = c.

Q: How do I solve a system of equations?

A: To solve a system of equations, you can use the following methods:

Substitution method: This involves substituting the expression for one variable from one equation into the other equation.
Elimination method: This involves adding or subtracting the equations to eliminate one of the variables.
Graphical method: This involves graphing the equations on a coordinate plane and finding the point of intersection.

Q: What is the substitution method?

A: The substitution method involves substituting the expression for one variable from one equation into the other equation. This is the method we used in our previous article to solve the system of equations.

Q: What is the elimination method?

A: The elimination method involves adding or subtracting the equations to eliminate one of the variables. This method is useful when the coefficients of one variable are the same in both equations.

Q: What is the graphical method?

A: The graphical method involves graphing the equations on a coordinate plane and finding the point of intersection. This method is useful when the system of equations has a simple solution.

Q: How do I determine which method to use?

A: To determine which method to use, you can try the following:

Check if the equations are linear: If the equations are linear, you can use the substitution or elimination method.
Check if the equations are nonlinear: If the equations are nonlinear, you may need to use a different method, such as the graphical method.
Check if the system has a simple solution: If the system has a simple solution, you may be able to use the graphical method.

Q: What are some common mistakes to avoid when solving systems of equations?

A: Some common mistakes to avoid when solving systems of equations include:

Not checking if the equations are linear or nonlinear: Make sure to check if the equations are linear or nonlinear before choosing a method.
Not using the correct method: Make sure to use the correct method for the type of system you are solving.
Not checking for extraneous solutions: Make sure to check for extraneous solutions, especially when using the substitution or elimination method.

Conclusion

In this article, we provided a Q&A guide to help you understand the concepts and methods used in solving systems of equations. We discussed the different types of systems of equations, the methods used to solve them, and some common mistakes to avoid. By following these guidelines, you can become more confident in your ability to solve systems of equations.

Final Answer

The final answer is that solving systems of equations requires a combination of algebraic skills, problem-solving strategies, and attention to detail. By mastering these skills and strategies, you can become proficient in solving systems of equations and tackle a wide range of mathematical problems.