To factor \(64 - 81a^2\), we recognize that this expression is a difference of squares.
The difference of squares formula is: \[ A^2 - B^2 = (A - B)(A + B) \]
In this case, we can identify:
- \(A = 8\) (since \(8^2 = 64\))
- \(B = 9a\) (since \((9a)^2 = 81a^2\))
Now, we apply the difference of squares formula: \[ 64 - 81a^2 = 8^2 - (9a)^2 = (8 - 9a)(8 + 9a) \]
Thus, the correct answer is: B) \(8^2 - (9a)^2 = (8 - 9a)(8 + 9a)\).