So to simplify fractions, you have to divide the numerator and denominator by their common GCF, or Greatest Common Factor. You would keep going until the numerator and denominator don't have a GCF greater than 1.
[tex] \frac{198}{726} /\frac{6}{6} =\frac{33}{121} \\ \\ \frac{33}{121} /\frac{11}{11} =\frac{3}{11} [/tex]
The simplified fraction is 3/11.