What are the linear and quadratic factors of 8x4−32x3−5x2+20x ?(1 point) Responses x(x−4)(8x2−5) x open paren x minus 4 close paren open paren 8 x squared minus 5 close paren x(x−4)(8x2+5) x open paren x minus 4 close paren open paren 8 x squared plus 5 close paren x(x+4)(8x2−5)

1 answer

To find the linear and quadratic factors of the polynomial \( 8x^4 - 32x^3 - 5x^2 + 20x \), we can first factor out the greatest common factor.

  1. Factor out the GCF: The GCF of the terms is \( x \), so we factor that out:

    \[ 8x^4 - 32x^3 - 5x^2 + 20x = x(8x^3 - 32x^2 - 5x + 20) \]

  2. Factor the cubic polynomial: Next, we need to focus on factoring the cubic polynomial \( 8x^3 - 32x^2 - 5x + 20 \). We can try synthetic division or apply the Rational Root Theorem to find possible rational roots.

    After testing a few values, we can find that \( x = 4 \) is a root.

    Now we perform synthetic division with \( x - 4 \):

    | 8   -32   -5    20
    4|      32   20    60
    ----------------------
       8     0   15    80
    

    The result shows that \( 8x^3 - 32x^2 - 5x + 20 = (x - 4)(8x^2 + 15) \).

  3. Putting it all together: We can now update our factored form:

    \[ 8x^4 - 32x^3 - 5x^2 + 20x = x(x - 4)(8x^2 + 15) \]

So the linear and quadratic factors of the original polynomial are:

  • Linear factors: \( x \) and \( (x - 4) \)
  • Quadratic factor: \( (8x^2 + 15) \)

Among the provided response options, the correct one is:

\( x(x - 4)(8x^2 + 15) \).

However, it appears there's an inconsistency in the options you provided (since the quadratic is stated as \( 8x^2 - 5 \) or other variations rather than what we've derived) and needs to be checked against the correct polynomial representation. If none match, the exact breakdown is:

\( x(x - 4)(8x^2 + 15) \) is the derived factorization.