Faci calcule [tex] (a-b)^2 =a^2 -2ab+b^2 [/tex]
[tex] (x-3)^2 +x(x+9) \\ x^2 -6x+9 +x^2 +9x \\ = 2x^2 +3x+9 [/tex]
Dacă vrei să descompui mai mult:
[tex] 2\left(x^2 +\dfrac{3}{2} x +\dfrac{9}{2} \right) = 2 \left( x^2 +2 x \dfrac{3}{4} +\left(\dfrac{3}{4} \right)^2 +\dfrac{63}{16} \right) \\ = 2 \left( x + \dfrac{3}{4} \right)^2 + \dfrac{63}{8} [/tex]
