Question 1060075
{{{x^2+y^2+ax+by+c=0}}}

{{{ax+by+c=-x^2-y^2}}}------the equations of your system will use this format.


Each given point makes an equation for the system.


{{{-5a-b+c=-(25+1)}}}
{{{-5a-b+c=-26}}}
{{{5a+b-c=26}}}
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{{{-11a-9b+c=-121-81}}}
{{{-11a-9b+c=-202}}}
{{{11a+9b-c=202}}}
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{{{-4a-8b+c=-(16+64)}}}
{{{-4a-8b+c=-80}}}
{{{4a+8b-c=80}}}
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Solve this system for a, b, c:
{{{system(5a+b-c=26,11a+9b-c=202,4a+8b-c=80)}}}


Solve the first of these for c, and substitute into the other two equations and get simpler system  {{{system(6a+8b=176,-a+7b=56)}}};


Equivalently this allows elimination of a:
{{{system(6a+8b=176,-6a+4b=336)}}};
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{{{highlight(b=42&2/3)}}}


The first equation in the last system is same as  {{{3a+4b=82}}}.
Use b to find a.
{{{3a=82-4b}}}
{{{3a=82-4(128/3)}}}
{{{a=(82-4(128/3))/3}}}
{{{highlight(a=-29&5/9)}}}