Factor –8x3 – 2x2 – 12x – 3 by grouping. What is the resulting expression? A. (2x2 – 3)(4x + 1) b. (–2x2 – 3)(–4x + 1) c. (2x2 – 3)(–4x + 1) d. (–2x2 – 3)(4x + 1)

Respuesta :

it's D
 (–2x2 – 3)(4x + 1)
frika

Consider the polynomial [tex] -8x^3 - 2x^2 - 12x - 3 [/tex]. You can group first two terms and second two terms:

[tex] -8x^3 - 2x^2 - 12x - 3= (-8x^3 - 2x^2 )+(- 12x - 3) [/tex].

Find the common factors in both brackets:

  • in brackets [tex] (-8x^3 - 2x^2 ) [/tex] the common factor is [tex] -2x^2 [/tex];
  • in brackets [tex](- 12x - 3) [/tex] the common factor is [tex] -3 [/tex].

Then rewrite the polynomial as

[tex] -8x^3 - 2x^2 - 12x - 3= (-8x^3 - 2x^2 )+(- 12x - 3) =-2x^2(4x+1)-3(4x+1) [/tex].

Here you see that expression 4x+1 is common, then

[tex] -8x^3 - 2x^2 - 12x - 3=-2x^2(4x+1)-3(4x+1)=(4x+1)(-2x^2-3). [/tex].

Answer: correct choice is D.