21/22 is already in simplest form
Write in lowest terms
18 over 21 in lowest terms is 6/7
75 over 21 in lowest terms = 25/7
21 over 12 in lowest terms = 7/4 or 13/4 or 1.75
8/21 is in its lowest form
21 over 49 in lowest terms is 3/7
The greatest common divisor is 3; if you divide both terms by 3, you get 6/7.
21/29 is a fraction in its lowest terms
Yes.
7 over 11
13/21 is in its simplest form.
21/42 = 1/2