Solving Quadratic Equations by Factoring

Solving Quadratic Equations by Factoring

Grade 10th Grade · Math · 15 min· Eureka Math

What's Included

Learning Objective

I can solve quadratic equations by factoring.

Reading Passage

Solving Quadratics by Factoring

Quadratic equations are polynomial equations with a degree of two. Solving them often involves finding the values of the variable that make the equation true. One common method for solving quadratic equations is factoring. Factoring breaks down the quadratic expression into a product of two linear expressions.

Consider the standard form of a quadratic equation: ax² + bx + c = 0, where a, b, and c are constants. The goal is to rewrite the quadratic expression as (px + q)(rx + s) = 0. Here, p, q, r, and s are also constants. When the product of two factors equals zero, at least one of the factors must be zero. This principle is called the zero-product property.

For example, let's solve x² + 5x + 6 = 0 by factoring. We need to find two numbers that multiply to 6 and add to 5. These numbers are 2 and 3. So, we can factor the equation as (x + 2)(x + 3) = 0. Setting each factor equal to zero gives x + 2 = 0 and x + 3 = 0. Solving these linear equations, we find x = -2 and x = -3. These are the solutions to the quadratic equation.

Factoring is a powerful technique, but it's not always straightforward. Some quadratic equations may require more advanced factoring techniques, or they may not be factorable at all using integers. In such cases, other methods like the quadratic formula are used.

Guided Notes

3 key concepts

  • 1

    A quadratic equation has a degree of two, and solving it means finding the values that make the equation true.

  • 2

    Factoring a quadratic expression involves breaking it down into a product of two linear expressions, such as (px + q)(rx + s) = 0.

  • 3

    The zero-product property states that if the product of two factors equals zero, then at least one of the factors must be zero.

Practice Questions

3 questions · Multiple choice & Short answer

Exit Ticket

Quick comprehension check

Solve the quadratic equation by factoring: x² - x - 12 = 0. Show all steps.

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