The simplified fraction of 15 over 63 is 5/21
2 over 21
It is 3/19
= 21/50
7/18
Yes. 21 over 54 can be simplfied to 7/18
21/57 = 7/19
5 over 7
7/12
21/45= 7/15
21 over 40 is irreducible as a fraction expression. 21 over 40 is 0.525 as a decimal expression.
The fraction 21/23 cannot be simplified. You could muliply both of them by the same number, and get a fraction like 42/46, but it's better to keep fractions simplified.