Salut,
[tex]Folosim\ formulele\ de\ calcul\ prescurtat:\\\\m^2-n^2=(m-n)(m+n);\\\\a^2-2\cdot a\cdot b+b^2=(a-b)^2.\\\\Expresia\ din\ enun\c{t}\ devine:\\\\F(x)=\dfrac{x^2-9}{x^2-6x+9}=\dfrac{\cancel{(x-3)}(x+3)}{(x-3)^{\cancel{2}}}=\dfrac{x+3}{x-3},\ x\neq3.[/tex]
Green eyes.
