10 over 42 in lowest terms = 5/21
21/10
75 over 21 in lowest terms = 25/7
18 over 21 in lowest terms is 6/7
21 over 12 in lowest terms = 7/4 or 13/4 or 1.75
21/30 = 7/10 in its lowest terms
8/21 is in its lowest form
21 over 49 in lowest terms is 3/7
21/29 is a fraction in its lowest terms
Yes.
7 over 11
21/35 = 3/5