(a) Find the greatest common factor (GCF) of 24 and 16.
\[
\mathrm{GCF}=
\]
(b) Use the GCF to factor $24-16$.
\[
24-16=\square \times(\square-\square
\]

Step 1 ：Find the greatest common factor (GCF) of 24 and 16. The greatest common factor (GCF) of two numbers is the largest number that divides both of them without leaving a remainder. To find the GCF of 24 and 16, we can use the Euclidean algorithm. This algorithm is based on the principle that the greatest common divisor of two numbers does not change if the larger number is replaced by its difference with the smaller number.

Step 2 ：The greatest common factor (GCF) of 24 and 16 is \(\boxed{8}\).

Step 3 ：Use the GCF to factor the expression 24 - 16.

Step 4 ：The expression 24 - 16 can be factored as \(8 \times (3 - 2)\).

Step 5 ：Final Answer: The greatest common factor (GCF) of 24 and 16 is \(\boxed{8}\). The expression 24-16 can be factored as \(8 \times (3 - 2)\).