Class Greeting
Chapter 6 – Factoring Lesson 6-3c Factoring Trinomials ax2 + bx + c by Grouping
Objective: The student will learn how to factor the by Grouping.
Factor by grouping. a = 15 and c = –8 therefore ac = –120 What 2 numbers multiply to make -120 and add to make –14? 6 and –20 Replace -14b with 6b – 20b Group 15b2 + 6b – 20b – 8 (15b2 + 6b) – 1(20b + 8) 3b(5b + 2) – 4(5b + 2) 6b –20b –14b TRUE Answer:
Factor by grouping. 4x2 + 27x – 40 a = 4 and c = –40 therefore ac = –160 What 2 numbers multiply to make -160 and add to make 27? 32 and –5 Replace 27x with 32x – 5x 4x2 + 32x –5x – 40 Group (4x2 + 32x) + (–5x – 40) 4x(x + 8) – 5(x + 8) (4x – 5)(x + 8) -5x 32x 27x TRUE Answer: (4x – 5)(x + 8)
Lesson Summary: Objective: The student will learn how to factor the by Grouping.
Preview of the next Lesson: Objective: The student will do a 6-1 to 6-3 practice test.
Kahoot!
Stand Up Please
Review: 6.3b Mini-Quiz 1. Factor 2x2 + 8x – 42 3. Factor 3x3 + 4x2 + 2x 4. Factor 9x2 – 24x + 15