Devi applicare la proprietà distributiva:
(x^2 - 3x + 4) * ( x - 1/2) =
= x^3 - 1/2 x^2 - 3x^2 + 3/2 x + 4x - (4 * 1/2) =
= x^3 - 1/2 x^2 - 3x^2 + 3/2 x + 4x - 2 =
= x^3 - 1/2 x^2 - 6/2 x^2 + 3/2 x + 8/2x - 2 =
= x^3 - 7/2 x^2 + 11/2 x - 2.
Ciao @giuly123