Respuesta :

b.)x³-7x²+3x+36

(x-4)(x²-3x-9)

Distribute x and -4 to x²-3x-9

=x²(x)-3x(x)-9(x)+x²(-4)-3x(-4)-9(-4)

=x³-3x²-9x-4x²+12x+36

Combine all liked terms

=x³-7x²+3x+36