To divide the polynomial \( x^3 - a^3 \) by \( x - a \), you can use polynomial long division or recognize that \( x^3 - a^3 \) is a difference of cubes.
The difference of cubes can be factored using the identity:
\[ x^3 - a^3 = (x - a)(x^2 + ax + a^2) \]
Now, let's perform the division:
- Divide the leading term \( x^3 \) by \( x \) which gives \( x^2 \).
- Multiply \( x^2 \) by \( x - a \) to get \( x^3 - ax^2 \).
- Subtract this from \( x^3 - a^3 \): \[ (x^3 - a^3) - (x^3 - ax^2) = ax^2 - a^3 \]
- Now, divide \( ax^2 \) by \( x \) which gives \( a \).
- Multiply \( a \) by \( x - a \) to get \( ax - a^2 \).
- Subtract this: \[ (ax^2 - a^3) - (ax - a^2) = ax^2 - ax + a^2 - a^3 \]
- Finally, when you perform the last subtraction, you'll end up with the remainder as \( a^2 \) minus \( a^3 \), confirming that there are no left terms.
Therefore, the identity established is:
\[ x^3 - a^3 = (x - a)(x^2 + ax + a^2) \]
So, the correct response is:
\( x^3 - a^3 = (x - a)(x^2 + ax + a^2) \).