lcd means least common denomenators
it is normally used to combine fractions with differnt denomenators
I can show 2 disproofs
so
they can be equal
conside
3/4 and 5/8
lcd is 8, 8>8 is false
not reasnable
they can be less if they arenot simplified
example
4/8 and 24/16
lcd is 4
not reasonable