If you reduce these fractions into simplest form 5/20 is 1/4 because the numerator and denominator can be divided by 5. 9/12 reduced is 3/4 because the numerator an denominator can be divided by 3.
[tex]\dfrac{5}{20}=\dfrac{5:5}{20:5}=\dfrac{1}{4}\\\\\dfrac{9}{12}=\dfrac{9:3}{12:3}=\dfrac{3}{4}[/tex]
