Question 847896
<pre>
{{{x^2-2xy+y^2}}}{{{""=""}}}{{{"0"}}}

{{{(x-y)(x-y)}}}{{{""=""}}}{{{"0"}}}

{{{(x-y)^2}}}{{{""=""}}}{{{"0"}}}

{{{x-y}}}{{{""=""}}}{{{"0"}}}

{{{x}}}{{{""=""}}}{{{"y"}}}

Edwin</pre>