It is simply 7 over 18, it can not be reduced further.
18/7 is in its simplest form.
18 over 14 in the simplest form = 9/7 or 12/7
18/21 in simplest form is 6/7.
18 over 63 is 2/7
it is 7 over 18
18/63 = 2/7
7/18 is already in its simplest form as a fraction
2/7
7/18
7/18
3/7
2/7