To factor the expression \( 81x - 36 \), we first look for the greatest common factor (GCF) of the two terms.
The GCF of \( 81x \) and \( 36 \) is \( 9 \). We can factor \( 9 \) out of the expression:
\[ 81x - 36 = 9(9x - 4) \]
Thus, the correct factorization is:
\[ 9(9x - 4) \]
So, the response that is equivalent to the expression \( 81x - 36 \) is:
9(9x−4)