factor them and find the common grouping
3/14
3 is prime so no factoring of this fraction
19/63, 63 is prime so no factoring
if ya wanted the least common denomenator then
14 and 63
14=2*7
63=7*9
so the least common denomenator would be 2*7*9=126
3/14 and 19/63 turns into 27/126 and 38/126