Question

what method of factoring should first be used?
3w + 21
answer
greatest common factor
difference of perfect squares
trinomial factoring
none of the above

Explanation:

The expression $3w + 21$ has terms sharing a common factor. First, identify the largest factor that divides both $3w$ and $21$, which is 3. This aligns with factoring out the greatest common factor, which is the appropriate first step.

Answer:

Greatest Common Factor