Question

How can you use the GCF of the numerator and the denominator to write a fraction in simplest form?

Answer 1

Take an example 

14 / 20

the GCF of 14 and 20 = 2  ( 20 = 2^2 * 5 and 14 = 2*7  so 2 is the GCF)

so we can divide top and bottom of the fraction by 2 to give 7/10 = simplest form