Question

Find the least number which must be subtracted from 8105 to make it a perfect square.I know the ans is 5 but gets confused while doing it practically. Plz send the proper prime factorisation method means "written"

I ll be grateful!!​

Answer 1

$\color{purple}\huge\bold\star\underline\mathcal{ꫝꫀꪶꪶꪮ}$