#### Answer

$3/5x$

#### Work Step by Step

In order to simplify fractions, we want to cancel out anything that is in both the numerator and the denominator of the fraction. In order to do this, we look for common factors for the values in the numerator and the denominator of the fraction. 12y and 20xy have a common factor of 4y, so we simplify:
$4y(3)/4y(5x)=3/5x$