Question 627633
write it:
n^2 - 25 = 0
add 25 to both sides and you have
n^2 = 25
n = {{{sqrt(25)}}}
n = +5
and
n = -5
:
Check replace n with 5: 
5^2 - 25 = 0
and
replace n with -5
(-5)^2 - 25 = 0