Question 19346
{{{ x*y = ((x+y)*(x+y-1))/4 }}}
This is only one equation. If there are two variables,a minimum of two unique equations are required to find the values of their given solutions. If there are three variable,three equations are neccessary,and so on.
<br>If you do simplify this,you'll get 
{{{(x-y)^2-(x+y)=0}}}
If you have one more equation,values of x and y can be obtained.
<P>
-Prabhat