Question 1054805
<pre>
{{{system(x+y =20,sqrt(xy) = 9)}}}

Square both sides of the second equation.
Solve by substitution.  Then use quadratic formula.

There are two real solutions.

solution #1:  {{{x=10 - sqrt(19)}}},{{{y=10 + sqrt(19)}}} 

solution #1:  {{{x=10 + sqrt(19)}}},{{{y=10 - sqrt(19)}}} 

Edwin</pre>