[tex]\displaystyle\bf\\a^2-b^2=12\\\\(a+b)(a-b)=12\\\\(a-b)=4~~~(din enunt)\\\\(a+b)\times4=12\\\\a+b=\frac{12}{4}\\\\\boxed{\bf a+b = 3}\\\\Raspuns~corect:~~\boxed{\bf d)~Ana}[/tex]
