Question

Considere os polinomios : A= -5x³ + 4x² - 9x + 5 ; B = 4x - 9 ; C = x² - 8 . Calcule :
(B+C). A 

Answer 1

 (4x - 9 + x² - 8)( -5x³ + 4x² - 9x + 5)

   (x² + 4x -17)( -5x³ + 4x² - 9x + 5)


- 5x^5 + 4x^4 - 9x^3 + 5x^2 - 20x^4 + 16x^3 - 36x^2 + 20x + 85x^3 - 68x^2 + 152x - 85

- 5x^5 - 16x^4 + 92x^3 - 99x^2 + 173x - 85

Answer 2

$(4x - 9 + x^2 - 8)( -5x^3 + 4x^2 - 9x + 5)= \\ \\ \\ (x^2 + 4x -17)( -5x^3 + 4x^2 - 9x + 5) =\\ \\ - 5x^5 + 4x^4 - 9x^3 + 5x^2 - 20x^4 + 16x^3 - 36x^2 + 20x + 85x^3 - 68x^2 + 152x - 85 = \\ \\\boxed{- 5x^5 - 16x^4 + 92x^3 - 99x^2 + 173x - 85}$