Question 1121286
{{{49x^2-36x+k}}}
{{{(7x-b)^2}}}
{{{49x^2-14bx+b^2}}}


{{{14b=36}}}
{{{b=36/14}}}
{{{b=18/7}}}


{{{k=b^2}}}

{{{k=(18^2)/(7^2)}}}

{{{highlight_green(k=324/49)}}}