To factor the expression \( 18m - 24n \) using the greatest common factor (GCF), we first need to determine what the GCF of the coefficients (18 and 24) is.
- The factors of 18 are: \( 1, 2, 3, 6, 9, 18 \)
- The factors of 24 are: \( 1, 2, 3, 4, 6, 8, 12, 24 \)
The greatest common factor of 18 and 24 is 6.
Now, we can factor out 6 from the expression:
\[ 18m - 24n = 6(3m - 4n) \]
So, the correct answer is:
6(3m − 4n)