Question

Aratati ca E(x) =3.
Repede va rog, dau coroana. :)

Answer 1

Răspuns:

Explicație pas cu pas:

E(x) = [( 2x² + 3x+1) / ( 2x+1) ]  - x + 2

E(x) = [ 2x² + 3x + 1 - ( x-2) ( 2x+1) ] / ( 2 x + 1 )

E(x) = [ 2x² + 3x + 1 - ( 2x²- 4x+x-2) ] / ( 2x+1)

E(x) = ( 2x² + 3x + 1 - 2x² + 3x + 2) / ( 2x+1)

E(x) = ( 6x +3) / ( 2x+1)

E(x) = 3(2x+1)/(2x+1)

E(x) = 3

Answer 2

$E(x) = \dfrac{2x^2+3x+1}{2x+1} - x+2 \\ \\ E(x) = \dfrac{2x^2+x+2x+1}{2x+1}-x+2 \\ \\ E(x) = \dfrac{x(2x+1)+2x+1}{2x+1}-x+2 \\ \\ E(x) = \dfrac{(2x+1)(x+1)}{2x+1}-x+2 \\ \\ E(x) = x+1-x+2 \\ \\ E(x) = 3$