Page 152 - MarceAlgebra Demystified

CHAPTER 6 Factoring 139

2
3: x þ 3x 10 ¼
2
4: x 6x þ 8 ¼
2
5: x 11x 12 ¼
2
6: x 9x þ 14 ¼
2
7: x þ 7x þ 10 ¼

2
8: x þ 4x 21 ¼
2
9: x þ 13x þ 36 ¼
2
10: x þ 5x 24 ¼

Solutions

2
1: x 5x 6 ¼ðx 6Þðx þ 1Þ

2 2
2: x þ 2x þ 1 ¼ðx þ 1Þðx þ 1Þ¼ðx þ 1Þ
2
3: x þ 3x 10 ¼ðx þ 5Þðx 2Þ
2
4: x 6x þ 8 ¼ðx 4Þðx 2Þ
2
5: x 11x 12 ¼ðx 12Þðx þ 1Þ
2
6: x 9x þ 14 ¼ðx 7Þðx 2Þ
2
7: x þ 7x þ 10 ¼ðx þ 5Þðx þ 2Þ
2
8: x þ 4x 21 ¼ðx þ 7Þðx 3Þ
2
9: x þ 13x þ 36 ¼ðx þ 4Þðx þ 9Þ
2
10: x þ 5x 24 ¼ðx þ 8Þðx 3Þ

2
There is a factoring shortcut when the first term is x . If the second sign is
plus, choose the factors whose sum is the coefficient of the second term. For
2
example the factors of 6 we need for x 7x þ 6 need to sum to 7: