Write the quadratic expression

Oct 13, 2025 by wbrum.org 141 views

Introduction to Factoring Quadratic Equations

Factoring quadratic equations is a crucial concept in algebra that involves expressing a quadratic expression as a product of two binomials. This technique is essential in solving quadratic equations, as it allows us to find the roots or solutions of the equation. In this article, we will explore how three students, Jordan, Keith, and Alex, used factoring to solve a quadratic equation.

The Quadratic Equation

The quadratic equation given to the students is:

${ x^2 + 17x + 72 = 12 }$

To begin solving this equation, we need to isolate the quadratic expression on one side of the equation. We can do this by subtracting 12 from both sides of the equation:

${ x^2 + 17x + 72 - 12 = 0 }$

This simplifies to:

${ x^2 + 17x + 60 = 0 }$

Jordan's Solution

Jordan's solution is as follows:

${ x^2 + 17x + 60 = (x + 15)(x + 4) = 0 }$

Jordan factored the quadratic expression by finding two numbers whose product is 60 and whose sum is 17. These numbers are 15 and 4, so Jordan wrote the quadratic expression as the product of two binomials:

${ (x + 15)(x + 4) = 0 }$

To find the solutions, Jordan set each binomial equal to zero and solved for x:

${ x + 15 = 0 \quad \text{or} \quad x + 4 = 0 }$

Solving for x, we get:

${ x = -15 \quad \text{or} \quad x = -4 }$

Keith's Solution

Keith's solution is as follows:

${ x^2 + 17x + 60 = (x + 12)(x + 5) = 0 }$

Keith also factored the quadratic expression by finding two numbers whose product is 60 and whose sum is 17. However, Keith's numbers are 12 and 5, so Keith wrote the quadratic expression as the product of two binomials:

${ (x + 12)(x + 5) = 0 }$

To find the solutions, Keith set each binomial equal to zero and solved for x:

${ x + 12 = 0 \quad \text{or} \quad x + 5 = 0 }$

Solving for x, we get:

${ x = -12 \quad \text{or} \quad x = -5 }$

Discussion

Both Jordan and Keith used factoring to solve the quadratic equation. However, their solutions differ. Jordan's solution is x = -15 or x = -4, while Keith's solution is x = -12 or x = -5.

To determine which solution is correct, we need to check if the solutions satisfy the original equation. We can do this by substituting each solution into the original equation:

${ (-15)^2 + 17(-15) + 72 = 12 }$

Simplifying, we get:

${ 225 - 255 + 72 = 12 }$

This simplifies to:

${ 42 = 12 }$

This is not true, so x = -15 is not a solution.

Next, we check if x = -4 is a solution:

${ (-4)^2 + 17(-4) + 72 = 12 }$

Simplifying, we get:

${ 16 - 68 + 72 = 12 }$

This simplifies to:

${ 20 = 12 }$

This is not true, so x = -4 is not a solution.

Now, we check if x = -12 is a solution:

${ (-12)^2 + 17(-12) + 72 = 12 }$

Simplifying, we get:

${ 144 - 204 + 72 = 12 }$

This simplifies to:

${ 12 = 12 }$

This is true, so x = -12 is a solution.

Finally, we check if x = -5 is a solution:

${ (-5)^2 + 17(-5) + 72 = 12 }$

Simplifying, we get:

${ 25 - 85 + 72 = 12 }$

This simplifies to:

${ 12 = 12 }$

This is true, so x = -5 is a solution.

Conclusion

In conclusion, Keith's solution is correct, and the solutions to the quadratic equation are x = -12 and x = -5. Jordan's solution is incorrect, and the solutions x = -15 and x = -4 do not satisfy the original equation.

Frequently Asked Questions

What is factoring in algebra?
How do you factor a quadratic expression?
What are the steps to solve a quadratic equation using factoring?

Step-by-Step Guide to Factoring Quadratic Equations

Write the quadratic expression: Write the quadratic expression in the form ax^2 + bx + c.
Find two numbers whose product is ac and whose sum is b: Find two numbers whose product is ac and whose sum is b.
Write the quadratic expression as the product of two binomials: Write the quadratic expression as the product of two binomials.
Set each binomial equal to zero and solve for x: Set each binomial equal to zero and solve for x.

Common Mistakes to Avoid

Not checking if the solutions satisfy the original equation: Make sure to check if the solutions satisfy the original equation.
Not using the correct method to factor the quadratic expression: Make sure to use the correct method to factor the quadratic expression.
Not following the steps to solve the quadratic equation: Make sure to follow the steps to solve the quadratic equation.

Final Thoughts

Factoring quadratic equations is a crucial concept in algebra that involves expressing a quadratic expression as a product of two binomials. This technique is essential in solving quadratic equations, as it allows us to find the roots or solutions of the equation. By following the steps outlined in this article, you can master the art of factoring quadratic equations and become proficient in solving quadratic equations.

Introduction

Factoring quadratic equations is a crucial concept in algebra that involves expressing a quadratic expression as a product of two binomials. This technique is essential in solving quadratic equations, as it allows us to find the roots or solutions of the equation. In this article, we will answer some frequently asked questions about factoring quadratic equations.

Q&A

Q: What is factoring in algebra?

A: Factoring in algebra involves expressing a quadratic expression as a product of two binomials. This technique is used to solve quadratic equations and find the roots or solutions of the equation.

Q: How do you factor a quadratic expression?

A: To factor a quadratic expression, you need to find two numbers whose product is ac and whose sum is b. These numbers are then used to write the quadratic expression as the product of two binomials.

Q: What are the steps to solve a quadratic equation using factoring?

A: The steps to solve a quadratic equation using factoring are:

Write the quadratic expression: Write the quadratic expression in the form ax^2 + bx + c.
Find two numbers whose product is ac and whose sum is b: Find two numbers whose product is ac and whose sum is b.
Write the quadratic expression as the product of two binomials: Write the quadratic expression as the product of two binomials.
Set each binomial equal to zero and solve for x: Set each binomial equal to zero and solve for x.

Q: What are some common mistakes to avoid when factoring quadratic equations?

A: Some common mistakes to avoid when factoring quadratic equations include:

Not checking if the solutions satisfy the original equation: Make sure to check if the solutions satisfy the original equation.
Not using the correct method to factor the quadratic expression: Make sure to use the correct method to factor the quadratic expression.
Not following the steps to solve the quadratic equation: Make sure to follow the steps to solve the quadratic equation.

Q: How do you know if a quadratic expression can be factored?

A: A quadratic expression can be factored if it can be written as the product of two binomials. To determine if a quadratic expression can be factored, you need to check if it can be written in the form (x + a)(x + b) = 0.

Q: What are some real-world applications of factoring quadratic equations?

A: Factoring quadratic equations has many real-world applications, including:

Physics: Factoring quadratic equations is used to solve problems involving motion, force, and energy.
Engineering: Factoring quadratic equations is used to design and optimize systems, such as bridges and buildings.
Computer Science: Factoring quadratic equations is used in algorithms and data structures.

Q: How do you factor a quadratic expression with a negative coefficient?

A: To factor a quadratic expression with a negative coefficient, you need to use the correct method to factor the quadratic expression. This involves finding two numbers whose product is ac and whose sum is b, and then writing the quadratic expression as the product of two binomials.

Q: What are some tips for mastering factoring quadratic equations?

A: Some tips for mastering factoring quadratic equations include:

Practice, practice, practice: The more you practice factoring quadratic equations, the more comfortable you will become with the technique.
Use the correct method: Make sure to use the correct method to factor the quadratic expression.
Check your work: Make sure to check your work to ensure that the solutions satisfy the original equation.

Conclusion

Factoring quadratic equations is a crucial concept in algebra that involves expressing a quadratic expression as a product of two binomials. This technique is essential in solving quadratic equations, as it allows us to find the roots or solutions of the equation. By following the steps outlined in this article, you can master the art of factoring quadratic equations and become proficient in solving quadratic equations.