Answer:
x³ + 4x² - 20x - 40
Step-by-step explanation:
Break it up into parts
(x+2)(x-4)(x+6)
( (x+2)(X-4) )(x+6)
Multiply (x+2)(x-4)
Breaking up the brackets, you get:
x(x-4)+2(x-4)
=x² - 4x + 2x -8
=x² - 2x - 8
Now multiply this by (x+6)
(x+6)(x² - 2x - 8)
= x³ - 2x² -8x + 6x²- 12x - 40
= x³ + 4x² - 20x - 40
