Answer
The number 3 is a FACTOR of both 9 and 12.
(used as a noun)
We can use this fact to FACTOR the expression $9x+12.$
(used as a verb)
(sample answer)
Work Step by Step
A factor, a multiple... (nouns).
Factoring an expression , to factor a polynomial ...(verbs).
Example:
The number 3 is a FACTOR (noun) of both 9 and 12.
We can use this fact to FACTOR (verb) the expression $9x+12.$