Question 366632

{{{ 9x^2+kx+36=(3x+n)^2 }}}
{{{ 9x^2+kx+36=9x^2+6nx+n^2}}}
Compare terms,
{{{n^2=36}}}
{{{n=0 +- 6}}}
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{{{kx=6nx}}}
{{{k=6n}}}
{{{k-n=6n-n}}}
{{{k-n=5n}}}
{{{highlight(k-n=0 +- 30)}}}