Math (Algebra)
posted by Lynn .
How do you simplify the following fraction;
72

68
I know the answer is
18

17
What I do not know is how this is the answer.The example I looked at did not tell me how it came to the answer. What do I do to find the answer?

divide the numerator by 4. Divide the denominator by 4.

Thank you, but how do I determine what number to divide by? So that I an solve other fractions like this one. Must I still find the greatest common number to divide by?

Yes. You find the largest common divisor to reduce a fraction.
Example?
10/15
Divide by 5
10/15 = 2/3 
Be careful. You posted (72)/(68) reduces to (18)/(17). You had a sign change in the numerator. Probably just a typo, but you might want to check.