21/77 in simplest form is 3/11, because both 21 and 77 are divisible by 7.
21/36 in simplest form is 7/12
It is already in its simplest form as a fraction.
21/7 in simplest form is 3/1 = 3
84/100 in its simplest form is 21/25
In its simplest form 525/1000 = 21/40
8/7
3/4
3/7
21/22 is already in simplest form
1/3
21/80 is already in its simplest form
105/441 = 5/21