Final answer:
The expression 9 + 5a + 12b is already in its simplest form, and its factors are the terms themselves: 9, 5a, and 12b. No further factoring or simplification is possible.
Step-by-step explanation:
The factors of the given expression 9 + 5a + 12b are the individual terms 9, 5a, and 12b themselves, as this is a sum of terms and not a product. Each term can be considered on its own.
To identify the factors of a term, we look for numbers and variables that can be multiplied together to get that term. The number 9 is a prime number and thus its only factors are 1 and 9. The term 5a has factors 5 and a, because 5 multiplied by a equals 5a. Lastly, the term 12b has factors 2, 2, 3, and b (because 2 * 2 * 3 * b = 12b).
When simplifying algebraic expressions, it's important to eliminate terms wherever possible. However, in this expression, there are no like terms to combine, so the expression is already in its simplest form. To ensure the answer is reasonable, we check each term and confirm there's no further simplification or factoring possible.