Warm-up: Factor Completely 5x2 + 5x – 30 6x2 – 12x – 378 2x2 – 12x 3x2 – 21x + 30
Factoring Trinomials when a is not equal to 1
How to Factor a Trinomial Check for GCF 1st. Divide out the GCF of each term if one exists. When factoring ax2 + bx + c, first find factors of a and c. Check the products of the inner and outer terms to see if the sum is b. When c is POSITIVE, both signs inside the parentheses will be the same as the middle term.
1. x2 + 9x + 14 +1 +2 +14 +7 1x ( + )( + ) x x 2 7
2. 2x2 – 5x + 3 1x 2x -1 -3 ( – )( – ) x 2x 1 3
3. 5x2 + 11x + 2 1x 5x +1 +2 ( + )( + ) x 5x 2 1
4. 3x2 – 10x + 3 1x 3x -1 -3 ( – )( – ) x 3x 3 1
5. 2x2 – 7x + 5 1x 2x -1 -5 ( – )( – ) x 2x 1 5
6. 6x2 – 11x + 3 1x 2x 6x 3x -1 -3 ( – )( – ) 2x 3x 3 1
7. 4x2 + 16x + 15 +1 +15 +3 +5 1x 2x 4x ( + )( + ) 2x 2x 3 5
8. 3x2 – 20x – 7 1x 3x 1 7 ( )( ) x 3x – + 7 1
9. 2x2 + 3x – 5 1x 2x 1 5 ( )( ) x 2x – + 1 5
10. 5m2 + 14m – 3 1m 5m 1 3 ( )( ) m 5m + – 3 1
11. 2x2 – 11x – 21 1x 2x 1 3 7 21 ( )( ) x 2x – + 7 3
Sometimes you can factor out a GCF 1st!
12. 14x2 – 32x + 18 2(7x2 – 16x + 9) 2( – )( – ) x 7x 1 9 1x 7x -1 -9 -3 2( – )( – ) x 7x 1 9
Class Work Factoring WS