Question

what is the greatest common factor (gcf)?
for the expression at left, decide what the greatest common factor is.
ask yourself: what do the two terms have in common?
remember, we dont want the leading term to be negative.
-3x - 18

Explanation:

Step1: Identify terms and factors

The expression is $-3x - 18$, with terms $-3x$ and $-18$. The numerical coefficients are $-3$ and $-18$. We consider positive factors first (to avoid negative leading term later): factors of $3$ are $1,3$; factors of $18$ are $1,2,3,6,9,18$.

Step2: Find greatest common factor

The largest common positive factor of $3$ and $18$ is $3$. There is no common variable factor (only the first term has $x$).

Answer:

$3$