Example

Factoring 18n237n+1518n^2 - 37n + 15

Factor 18n237n+1518n^2 - 37n + 15 using the trial and error method. This example highlights the value of the greatest common factor (GCF) elimination shortcut when the leading coefficient has multiple factor pairs.

Step 1: Write in descending order (already done). Step 2: The first term, 18n218n^2, factors as n18nn \cdot 18n, 2n9n2n \cdot 9n, or 3n6n3n \cdot 6n. Step 3: The last term, 15, is positive, and the middle coefficient, -37, is negative. Thus, use negative factors of 15: -1 and -15, or -3 and -5. Step 4: Test combinations. Instead of testing all arrangements, use the GCF elimination shortcut. Since the original trinomial has no GCF, any trial binomial with a common factor can be rejected. For example, (3n3)(6n5)(3n - 3)(6n - 5) is invalid because 3n3n and -3 share a factor of 3. After eliminating invalid binomials, test the remaining options: (2n3)(9n5)=18n210n27n+15=18n237n+15(2n - 3)(9n - 5) = 18n^2 - 10n - 27n + 15 = 18n^2 - 37n + 15 Step 5: The correct factored form is (2n3)(9n5)(2n - 3)(9n - 5).

Image 0

0

1

Updated 2026-06-28

Tags

OpenStax

Elementary Algebra @ OpenStax

Ch.7 Factoring - Elementary Algebra @ OpenStax

Algebra

Math

Prealgebra

Related
Learn After