Question 176996
( x – 4)(2x2 + 4) + ( x + 4)(x3 – 1) – ( x2 – x – 1) 
{( x – 4)(2x2 + 4)}       +       {( x + 4)(x3 – 1)}       {–   ( x2 – x – 1) }


First, simplify the last of these 3 sections so we don't forget that the minus sign applies to all 3 of the last terms and that if we are subtracting a negative x, it is really adding x.

( x – 4)(2x^2 + 4)        +       ( x + 4)(x^3 – 1)              – x^2 + x + 1

Then multiply each term in the binomials by the other terms.  Watch the signs.

x*2x^2 + x*4 -4*2x^2 -4*4 +   x*x^3 - x*1 + 4*x^3 – 4*1       – x^2 + x + 1
2x^3 + 4x - 8x^2 - 16 +   x^4 - x + 4x^3 – 4       – x^2 + x + 1

Reorganizing the terms:
x^4 + 2x^3 + 4x^3 - 8x^2 – x^2 +    4x - x          + x - 16 + 1– 4

Now, combine like terms:
x^4 + 6x^3  - 9x^2  +    4x   - 19