E(x)=(x+1)² +2(x-7)+1
(x+1)² +2(x-7)+1 = 0 => x² +2x+1+2x-14+1 = 0 =>x² +4x-12 = 0
Δ = 16+48 =64 =>
[tex]x_{1,2} = \frac{-4\pm8}{2} \Rightarrow \left \{ {{x_1=2} \atop {x_2=-6}} \right. \\ \\ $ \ Stim ca la o ecuatie de gradul 2: ax^2+bx+c = 0 \\ $ ax^2$ +bx+c $ $ poate fi scrisa $ $ a(x-x_1)$(x-x_2)\\ \\ $ la noi ecuatia este x^2+4x-12 = 0 \Rightarrow \\ \\ \Rightarrow E(x) = x^2+4x-12 = 1\cdot(x-2)(x-(-6)) \Rightarrow \\ \Rightarrow E(x) = (x-2)(x+6)[/tex]
