Răspuns:
{[(3a+5)×3+5]×3+5}×3+5=281
{[(3a+5)×3+5]×3+5}×3=281-5
[(3a+5)×3+5]×3+5=276:3
[(3a+5)×3+5]×3=92-5
(3a+5)×3+5=87:3
(3a+5)×3=29-5
3a+5=24:3
3a=8-5
a=3:3
a=1
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coroana!
