In Pythagoras triplet problem
if mn = N/21 so how can we write m=N/2 and n=1 , there can be different pairs of n and m satisfying the equation it is not necessary that n will be equal to 1.
Like for eg: m*n=18
then it is not necessary that m=18 and n=1 we can have other pair like m=6 and n=3…