Question 1109568
{{{system(x+y=20,xy=99)}}}


{{{x(20-x)=99}}}
{{{-x^2+20x-99=0}}}
{{{x^2-20x+99=0}}}
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{{{D=400-4*99=400-496=2^2}}}
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{{{x=(20+- 2)/2}}}
{{{system(x=9,or,11)}}}


The numbers are 9 and 11.


Simply factoring 99 into {{{9*11}}} might be enough to quickly find this answer.