___ ___ ___
xxy = { xx0 ; xx5 }
\a) daca x+x+0=9 => numerele: ∅
x+x+5=9 => - ,, - 225 ;
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b) daca x+x+0=19 => - ,, - ∅
x+x+5=19 => - ,, - 775;
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c) daca x+x+0=27 => - ,, - ∅
x+x+5=27 => - ,, - ∅