Question 1163433
{{{system(x-4,and,x^2+(x-4)^2=72)}}}


{{{x^2+x^2-8x+16=72}}}


{{{2x^2-8x=56}}}
{{{x^2-4x=28}}}
{{{cross(x^2-4x+4=56+4)}}}-----------------WRONG.  

(the rest, removed)