Explanation:
No, this is incorrect.
You might have made an small error when using distributive law method at the step where you have to multiply \(-9\) and \(81\) together. Keep in mind that when multiplying a positive number with a negative number, the product should be negative.
Alternatively, you might have used the sum of two cubes equation instead of the difference of two cubes. A trick is to look at the first bracket. If there is a minus inside, you should use the difference of two cubes equation. Similarly, if the sign inside the first bracket is a plus, then you should use sum of two cubes.
C: