Relax

Respuesta :

Answer:

Four

Step-by-step explanation:

Let's expand and see how many nonzero terms:

⇒ (x+4)(2x²+3x+9)-3(x³-2x²+7x)=

⇒ 2x³ + 3x² + 9x + 8x² + 12 + 36 - 3x³ + 6 x² - 21 x=

⇒ - x³ + 17x² - 12x + 12

As we see the expression has four nonzero terms