Problem:
Multiply (x + x2 + x + 1) (3x2 + 3x-3) (x3 + x2 + x + 1) (3x2 + 3x - 3)
Solution:
[tex](x+x^2+x+1)(3x^2+3x-3)(x^3+x^2+x+1)(3x^2+3x-3)[/tex]this is equivalent to:
[tex](2x+x^2+1)(3x^2+3x-3)(x^3+x^2+x+1)(3x^2+3x-3)[/tex]this is equivalent to:
[tex](2x+x^2+1)(x^3+x^2+x+1)(3x^2+3x-3)^2[/tex]this is equivalent to:
[tex]9x^9+45x^8+\text{ 81}x^7+63x^6+18x^5-18x^4-45x^3-27x^2+9x+9[/tex]Then, the correct answer is:
[tex]9x^9+45x^8+\text{ 81}x^7+63x^6+18x^5-18x^4-45x^3-27x^2+9x+9[/tex]