Simplify the following polynomial expression.
(5x^4 - 9x^3 + 7x - 1) + (-8x^4 +
4x^2– 3x + 2) - (-4x^3 + 5x - 1)(2x -7)
A 5x^4 - 37x^3 - 6x^2 + 41x - 6
B. 11x^4- 21x^3 + 14x^2 + 33x-8
C. 11x^4- 21x^3 + 14x^2 + 33x- 6
D. 5x^4– 37x^3- 6x^2 + 4x - 8

Respuesta :

Answer:

A. [tex]5x^4 - 37x^3 - 6x^2 + 41x - 6[/tex]

step-by-step-explanation:

  • [tex](5x^4 - 9x^3 + 7x - 1) + (-8x^4 +4x^2- 3x + 2) - (-4x^3 + 5x - 1)(2x -7)[/tex]
  • [tex](5x^4 - 9x^3 + 7x - 1) -8x^4 +4x^2- 3x + 2 - (-8x^4+28x^3+10x^2-37x+7)[/tex]
  • [tex]5x^4 - 9x^3 + 7x - 1-8x^4 +4x^2- 3x + 2 +8x^4-28x^3-10x^2+37x-7[/tex]
  • [tex]5x^4 -8x^4 + 8x^4 -9x^3 -28x^3 +4x^2 -10x^2 +37x +7x -3x -7 -1 +2[/tex]
  • [tex]5x^4 - 37x^3 - 6x^2 + 41x - 6[/tex]

Answer:

[tex]5x^4- 37x^3-6x^2+ 41x-6[/tex]

Step-by-step explanation:

simplify the following expression:  

[tex](5x^4 - 9x^3 + 7x - 1) + (-8x^4 +4x^2-3x + 2) - (-4x^3 + 5x - 1)(2x -7)[/tex]

Expand [tex](-4x^3 + 5x - 1)(2x -7)[/tex]

[tex]\implies -8x^4 +28x^3+10x^2-35x-2x+7\\\\\implies -8x^4 +28x^3+10x^2-37x+7\\[/tex]

Therefore:

[tex](5x^4 - 9x^3 + 7x - 1) + (-8x^4 +4x^2- 3x + 2)-(-8x^4 +28x^3+10x^2-37x+7)[/tex]

Group and combine like terms:

[tex]5x^4 -8x^4- 9x^3 +4x^2+ 7x - 3x- 1 + 2-(-8x^4 +28x^3+10x^2-37x+7)\\\\\implies -3x^4- 9x^3 +4x^2+ 4x +1-(-8x^4 +28x^3+10x^2-37x+7)[/tex]

Apply the distributive rule:  [tex]-(-a+b)=a-b[/tex]

[tex]\implies -3x^4- 9x^3 +4x^2+ 4x +1+8x^4-28x^3-10x^2+37x-7[/tex]

Group and combine like terms:

[tex]\implies -3x^4+8x^4- 9x^3 -28x^3+4x^2-10x^2+ 4x+37x +1-7\\\\\implies 5x^4- 37x^3-6x^2+ 41x-6[/tex]