No.
7 over 80 reduced to in a fraction = 7/80
13/21 can't be reduced.
The fraction 3/80 cannot be reduced any more.
21/40 cannot be reduced.
21/80 is already in its simplest form
25/21 is already reduced to its lowest terms
50/80 = 5/8
Since both numbers are even numbers, yes 78/80 can be reduced.
21 / 80
reduced fraction of 74 over 160 = 37/80
736 and 21 are comprime so the fraction cannot be reduced.
The fraction 19/21 cannot be reduced any more.