A:\(\frac{1919}{7373}=\frac{1919:101}{7373:101}=\frac{19}{73}\)
\(\frac{454545}{818181}=\frac{454545:10101}{818181:10101}=\frac{45}{81}=\frac{5}{9}\)
\(\frac{234234}{361361}=\frac{234234:1001}{361361:1001}=\frac{234}{361}\)
B: \(\frac{17}{18}=\frac{1}{2}+\frac{1}{3}+\frac{1}{9}\)