Question

Fie expresia E
$( x) = {x}^{2} - 5 x + 6 + (x + 2)(x - 3)$
Valoarea expresiei pentru
$x = 2 \: este$

Answer 1

$\it E(x) =x^2-5x+6+(x+2)(x-3)=x^2-3x-2x+6+(x+2)(x-3)=\\ \\=x(x-3)-2(x-3) +(x+2)(x-3)=(x-3)(x-2+x+2)=(x-3)\cdot 2x\\ \\ E(2)=(2-3)\cdot 2\cdot2=-1\cdot4=-4$