Which of the following expressions represents the GCF of 91x 2 y and 104xy 3?

13xy

728x 2y 3

13x 2y

728xy

The greatest common factor is found by finding the product of common primes.

91=7*13, 104=2*2*2*13 so the gcf of 91 and 104 is 13. Since the highest power of x and y in both terms is 1, the hcf for the variables is just xy

13xy