Factoring Polynomials Section 2.4 Standards Addressed: A1.1.1.5, A1.1.1.5.3, CC.2.2.HS.D.1, CC.2.2.HS.D.2, CC.2.2.HS.D.5 Essential Questions How does the FOIL method relate to factoring quadratic trinomials and a difference of two squares? Why should we factor? Factoring Checklist Factor out the GCF. If the polynomial has two or three terms, look for: A quadratic trinomial (which can result in a pair of binomial factors) A difference of two squares Check that each factor is prime. Check your answer by multiplying all of the factors. A quadratic trinomial is a trinomial that is in the format ax2 + bx + c, where a, b, and c are integers. We will only be working with quadratic trinomials where a = 1. Factoring a quadratic trinomial involves recognizing patterns, estimating, looking for clues, and multiplying to check. ax2 + bx + c Quadratic trinomials can often be factored as a product of two binomials. To do so, determine which two numbers have a product equal to c and a sum equal to b. Example 1: Factor A. 𝑥 2 + 7𝑥 + 10 Factors of _____ whose sum is _____ B. 𝑚2 − 5𝑚 + 6 Factors of _____ whose sum is _____ Example 1: Factor C. 𝑦 2 − 5𝑦 − 24 Factors of _____ whose sum is _____ D. 𝑥 2 + 18𝑥 − 63 Factors of _____ whose sum is _____ Worksheet: Factoring Trinomials Some binomials can be factored as a difference of two squares. a2 – b2 = (a + b)(a – b) Example 2: Factor A. 𝑥2 − 9 B. 4𝑚2 − 25 C. 9𝑥 2 + 81 Always check to make sure all polynomials are factored completely. Example 3: Factor A. 2𝑘 2 − 50 B. 3𝑦 2 + 45𝑦 − 48 C. −5𝑑2 − 45𝑑 − 90