Question 1087016
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<pre>
{{{(x-y)^2}}} = 71 = {{{x^2 - 2xy + y^2}}} = {{{(x^2 + y^2)}}} - {{{2xy}}} = 59 - 2xy  ====+

-2xy = 71 - 59 = 12  ====>  xy = {{{12/(-2)}}} = -6.
</pre>

Solved.