Which of the following is a factor of x3 − 1331?

x − 11
x2 − 11x + 121
x2 + 22x + 121
None of the above

1 answer

To determine which of the given options is a factor of \( x^3 - 1331 \), we can start by rewriting \( 1331 \) as \( 11^3 \). Therefore, we have:

\[ x^3 - 1331 = x^3 - 11^3 \]

This expression can be factored using the difference of cubes formula:

\[ a^3 - b^3 = (a - b)(a^2 + ab + b^2) \]

In our case, \( a = x \) and \( b = 11 \), so we can apply the formula:

\[ x^3 - 11^3 = (x - 11)(x^2 + 11x + 121) \]

Now, we will analyze the provided options:

  1. \( x - 11 \): This is one of the factors we found, \( (x - 11) \).

  2. \( x^2 - 11x + 121 \): We need to check if this is a factor. Notice that it does not appear in our factorization.

  3. \( x^2 + 22x + 121 \): Again, this does not appear in our factorization as well.

Since our factorization shows that \( x - 11 \) is indeed a factor of \( x^3 - 1331 \), we can conclude:

The answer is \( x - 11 \).