Lesson 5: Solving Quadratic Equations by Factoring

• How do we solve quadratic equations?
• What is the zero product property?
• Why does factoring help us solve?
• How do we check our solutions?

Quadratic equation, zero product property, factor, solution, root

CCSS.MATH.9.A.REI.B.4

Description: Students learn that if a product equals zero, one of the factors must be zero (zero product property). They factor quadratic equations and use this property to solve them. Graphically, they see that solutions are the x-intercepts (where the parabola crosses the x-axis). Purpose: To develop understanding of solving quadratics and connect algebraic and graphical solutions. DOK Level: 2-3 (Application and Strategic Thinking)

• Graphical connection: Show where solutions appear on the parabola
• For struggling learners: Solve equations already factored; focus on finding x values
• For advanced learners: Solve equations requiring factoring first
• Zero product property poster: Display the key concept visually

• Observation: Do students understand zero product property?

• Worksheet: Solve 4 quadratic equations by factoring

• Check-your-work: Substitute solutions back into the original equation

• Graphical verification: Show solutions on a graph

• Zero product property explanation and visual

• Pre-factored and unfactored quadratic equations

• Practice worksheets

• Verification worksheet

• Graphing tools (Desmos)

• Resource: Khan Academy "Solving Quadratics by Factoring" (adapted)