Answer
5/7
Work Step by Step
We need to find the greatest common factor for the numbers in the numerator and the denominator in order to simplify the fractions. Then, we can divide both the numerator and the denominator by the greatest common factor to get the simplified form of the fraction. The greatest common factor of 20 and 28 is 4, so we divide the fraction by 4/4 to get the simplified form: 5/7.