Solution (By Examveda Team)
$$\eqalign{
& {\text{Let }}m = \sqrt {5 + \sqrt {5 + \sqrt 5 } } \cr
& {\text{Factor}} = \left( a \right) \times \left( {a + 1} \right) \cr
& {\text{Here }}m = a + 1 \cr
& \Rightarrow m - 1 = a\,.........(i) \cr
& {\text{Let }}n = \sqrt {5 - \sqrt {5 - \sqrt 5 } } \cr
& {\text{Factor}} = \left( a \right) \times \left( {a + 1} \right) \cr
& {\text{Here }}n = a\,.........(ii) \cr
& {\text{From (i) & (ii)}} \cr
& \Leftrightarrow m - 1 = n \cr
& \Leftrightarrow m - n - 1 = 0 \cr} $$
Why factor taken as (a×(a+1)) and m=a+1,n=a