Answer:
x^4 -x^3 -9x^2 -11x -4
Step-by-step explanation:
We can use the zero product property
(x-a) (x-b) (x-c) (x-d) where a b c d are the roots
(x- -1)(x- -1)(x- -1) ( x-4) since the root -1 is repeated 3 times and 4 is a root
(x+1)(x+1)(x+1) ( x-4)
Foil the first two terms and the last two terms
(x^2 + 2x+1)( x^2 -3x-4)
Foil again
x^4 -3x^3 -4x^2 +2x^3 -6x^2 -8x +x^2 -3x-4
Combine like terms
x^4 -x^3 -9x^2 -11x -4
