13/21 can't be reduced.
Reduced to its most simplified form, 21 over 12 (or 7/4) is "one and three-quarters" 13/4
21/40 cannot be reduced.
2/13 is in reduced form
25/21 is already reduced to its lowest terms
21
The fraction 19/21 cannot be reduced any more.
736 and 21 are comprime so the fraction cannot be reduced.
No.
6/13 is in lowest terms and can't be reduced.
Yes, 21/3 = 7/1
No, 21 over 32 cannot be reduced.
No.