Factoring Trinomials: Methods and Examples
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Presentation Transcript
Chapter 5 Section 4 Factoring Trinomials
Findtwonumbers • Sum is 11, product is 24 • Sum is -14, product is 40 • Sum is 10, product is -24 • Sum is -7, product is -30
Area Model Factor: Sum is 11, product is 24. Two numbers are: 8 and 3 Make a box with 4 square inside.
Area Model • Factor: 2x2 8x • 3x 12 • Find the common factors and write on top and on the left side.
Factor 2x2 + 11x+12 x 4 2x 2x2 8x 3 3x 12 Answer: (x + 4)(2x + 3)
Factor 2x2 + 11x+12 • Grouping • Sum is 11, product is 24 • Two number are 3 and 8 • Rewrite the middle (linear) term using the two numbers. • 2x2 + 3x + 8x +12 • Factor by groups.
Continue • 2x2 + 3x + 8x +12 • Factor by groups • (2x2 + 3x) + (8x +12) • Common factor • x(2x + 3) + 4(2x + 3) • (2x + 3)(x + 4)
Try • Factor: 3x2 + 8x + 5
Look at this • Factor: 3x2 + 3x – 18 • Note: Find the common factor first.
On paper • Factor: 3x2 + 3x – 18
Factor e) f) g)
Factor h) i) j)
Summary • Found two numbers that were the sum and product. • Factored a trinomial • Area model • grouping