Find the GCF of the numerator and the denominator and divide them both by it. If the GCF is 1, the fraction is in its simplest form.
2/5
1/2
11/40 is in its lowest terms.
14/45 is already a fraction in its lowest terms.
1/7
As an improper fraction in its lowest terms it is 269/20
The lowest term has already been reduced as far as it will go. It is not possible to reduce it further.
3/5
5/9
2
-2/5
2/5
1/2
if you mean 40/64 then it is 5/8 in its lowest terms
11/40 is in its lowest terms.
14/45 is already a fraction in its lowest terms.
4/9