270 likes | 413 Views
Warm-Up – p. 287 #26-30 even. Solve for x: 26) 8 – 2x 2 = -3 28) (t + 2) 2 = 7 30) 4(s 2 + 7) – 9 = 39. Homework Questions?. PSAT Questions?. Factoring Quadratics. Lesson 5.3. Essential Question. How can we factor quadratics?. What is factoring?.
E N D
Warm-Up – p. 287 #26-30 even • Solve for x: • 26) 8 – 2x2 = -3 • 28) (t + 2)2 = 7 • 30) 4(s2 + 7) – 9 = 39
Factoring Quadratics Lesson 5.3
Essential Question • How can we factor quadratics?
What is factoring? • Factoring is writing an expression as the product of two or more expressions. • Factoring is the opposite of distributing. Distributing Factoring
Methods of Factoring • Greatest common factor • Difference of two perfect squares • Perfect-square trinomials • Factoring x2 + bx + c • Factoring ax2 + bx + c
Find the greatest common factor (GCF) of all terms. Divide each term by the greatest common factor. Write the GCF outside parenthesis, with the rest of the divided terms added together inside 3a2 – 12a 3a is the GCF Factoring out greatest common factor
Factoring x2 + bx + c • Look for integers r and s such that: • r × s = c • r + s = b 1c r s b
You-Trys – Factor each expression • x2 + 5x + 6 • x2 – 10x – 11 • y2 – 5y + 4
Factoring ax2 + bx + c • Many methods • Guess and check • Modified “big X” method used for a=1 • Split “bx” and factor by grouping
Factoring ax2 + bx + c similar to a=1 • You MUST factor out the GCF first. • Look for integers r and s such that: • r × s = ac • r + s = b • Divide r and s by a, then reduce fractions • In your factors, any remaining denominator gets moved in front of the x ac r s b
You-Trys – Factor Each Expression • 2x2 + 3x + 1 • 3x2 + 10x + 3 • 12x2 – 3x – 9
Assignment • Page 296 #31-57 odd
Warm-Up: October 22, 2012 • Multiply each of the following:
Factoring Quiz • 10 questions, 3 points each • 30 points possible • Retake available starting tomorrow • No quiz corrections required to retake this quiz • Retake will be similar to, but not identical to, the original quiz
Factoring Steps • Always factor out the GCF first. • If there are only two terms, check for difference of perfect squares • If there are three terms, check for perfect square trinomial • Use the Big X for three terms that are not perfect square trinomials.
Assignment • Factoring worksheet