Question 62825
{{{sqrt(n+9)+3=n}}} Subtract 3 from each side
{{{sqrt(n+9)+3-3=n - 3}}}
{{{sqrt(n+9)=n - 3}}} Square each side
{{{n+9=(n - 3)^2}}}
{{{n+9=n^2 - 6n + 9}}} Subtract 9 from each side
{{{n+9-9=n^2 - 6n + 9-9}}}
{{{n=n^2 - 6n }}} Subtract n from each side
{{{n-n=n^2 - 6n -n}}}
{{{0=n^2 - 7n}}}
{{{0=n(n-7)}}} 
ie n = 7 or n = 0