Question 736621
{{{12-6sqrt(9n)=0}}}

{{{12-6sqrt(3^2n)=0}}}

{{{12-6*3sqrt(n)=0}}}

{{{12-18sqrt(n)=0}}}

{{{12=18sqrt(n)}}}

{{{12/18=sqrt(n)}}}

{{{2/3=sqrt(n)}}}

{{{(2/3)^2=(sqrt(n))^2}}}

{{{4/9=n}}}