Răspuns :
9x^2-4 se poate scrie (3x+2)(3x-2) 18x^2+12x+8 se poate scrie si ca (3x+2)(6x+4) (3x+2)(3x-2) supra (3x+2)(6x+4) se simplifica 3x+2 de sus si de jos si ramane (3x-2) supra (6x+4)
[tex]\bullet 18x^2+24x+8=18x^2+12x+12x+8=6x(3x+2)+4(3x+2)=\\
=(3x+2)(4+6x)=2(3x+2)^2\\
\bullet 9x^2-4=(3x-2)(3x+2)\\
\dfrac{9x^2-4}{18x^2+24x+8}=\dfrac{(3x+2)(3x-2)}{2(3x+2)^2}=\dfrac{3x-2}{2(3x+2)}[/tex]
