<PRE><B>Question 1163920</B>
{{{system(x-y=9,x^2+y^2=653)}}}

-

{{{x^2-2xy+y^2=653-2xy}}}
{{{x^2+y^2=653-2xy}}}
.
.
{{{286=xy}}}


Look at first equation and see {{{x=y+9}}}.
Substitute.
{{{286=y(y+9)}}}------------factorize and look for if possible two factors differing  by 9.


{{{286=highlight(22*13)}}}


13  and  22


OR


-13  and  -22</PRE>