SOLUTION: I believe I have done this one right but if someone could please confirm? Multiply as required and collect terms: (x - 4) (2x^2 + 4) + (x + 4)(x^3 - 1) - (x^2 - x -n 1) OK

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I believe I have done this one right but if someone could please confirm? Multiply as required and collect terms: (x - 4) (2x^2 + 4) + (x + 4)(x^3 - 1) - (x^2 - x -n 1) OK      Log On


   

Question 172919: I believe I have done this one right but if someone could please confirm?
Multiply as required and collect terms:
(x - 4) (2x^2 + 4) + (x + 4)(x^3 - 1) - (x^2 - x -n 1)
OK! This is what I have:
(x - 4)+(x +4)(x^3 - 1) =
x^5 - 1)(2x^2 + 4)-(x^2 - x - 1)=
(4x^7 + 3)-(x^2 - x - 1) =
(4x^7 + 3)-(x - 1)=
4x^6 +2
Is this correct? Thanks for any help available?
Answer by monika_p(71) About Me  (Show Source):
You can put this solution on YOUR website!
(x - 4) (2x^2 + 4) + (x + 4)(x^3 - 1) - (x^2 - x - 1)
First you have do multiplication using distributive property (a+b)(c+d)=ac+ad+bc+bd
(x*2x^2+x*4-4*2x^2-4*4) + (x*x^3+x*(-1)+4*x^3+4*(-1))-(x^2-x-1)= remove brackets and remember to change sign if there is - before (...)
2x^3+4x-8x^2-16+x^4-x+4x^3-4-x^2+x+1= add like items
x^4+6x^3-9x^2+4x-19