![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Method 1:
\List the factors of each number.
\Factors of 34 : 2, 17, 34
\Factors of 85 : 5, 17, 85
\Identify the greatest common factor.
\The greatest common factor of 34 and 85 is 17.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Method 2:
\Write the prime factorization of each number.
\34 = 2 × 17.
\99 = 5 × 17.
\The GCF is the product of the common prime factors in each number.
\GCF = 17.
\The greatest common factor of 34 and 85 is 17.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The greatest common factor of 34 and 85 is 17.
\