Answer :
so if we assume that the ending fraction has to be equal to the origonal fraction then we multiply it by 1 or x/x where x=x
so 4/5 times 2/2=8/10
4/5 times 3/3=12/15
and so on
so 4/5 times 2/2=8/10
4/5 times 3/3=12/15
and so on