9-4 Factoring Trinomials ax² + bx + c

Factoring Trinomials like ax² + bx + c is also known as factoring trinomials with a number in front. To factor this polynomial your first step would be to multiply numbers a and c. You then take your product of ac and find two factors of it which add up to b. Once you find your factor pair you have to find out whether the signs are the same or different. If they're the same just simply plug in the numbers, but if they're different you have to determine which one takes which sign. Then, just group and find a GCF in each pair. Once you find out the GCF take it out. What's left inside and outside the parantheses is your answer.

http://www.ltcconline.net/greenl/courses/152B/FactoringRatExpr/factor.htm

http://www.algebrahelp.com/lessons/factoring/trinomial/

Ax²+ Bx+ C
1. Multiply A and C
2. Find the factor pairs of A and C
3. Rewrite Busing the factor pairs of A and C
4. Continue factoring using Grouping

Example
5x²+ 27x+ 10
5x10=50
1-50
2-25
4-25
5-10
(5x²+2x)+(25x+10)

x(5x+2)+5(5x+2)

(x+5)(5x+2)

Example
2x²-3x-2
2x-2=-4
1-4
2-2
(2x²-4x)+(x-2)

2x(x-2)+1(x-2)

(2x+1)(x-2)