Which one has its result equal to \( 1 ? \) \[ \begin{array}{l}\frac{9}{8} \div \frac{81}{64} \\ \frac{3}{3} \div 6 \frac{2}{12} \\ 4\end{array} \] \[ \]

To find which expression has a result equal to 1, we need to simplify each expression and check if the result is 1. 1. \(\frac{9}{8} \div \frac{81}{64}\): - Simplify the division by multiplying by the reciprocal of the divisor: \(\frac{9}{8} \div \frac{81}{64} = \frac{9}{8} \times \frac{64}{81}\) - Multiply the numerators and denominators: \(\frac{9}{8} \times \frac{64}{81} = \frac{9 \times 64}{8 \times 81} = \frac{576}{648}\) - Simplify the fraction: \(\frac{576}{648} = \frac{8}{9}\) 2. \(\frac{3}{3} \div 6 \frac{2}{12}\): - Convert the mixed number to an improper fraction: \(6 \frac{2}{12} = \frac{6 \times 12 + 2}{12} = \frac{74}{12}\) - Simplify the division by multiplying by the reciprocal of the divisor: \(\frac{3}{3} \div \frac{74}{12} = \frac{3}{3} \times \frac{12}{74}\) - Multiply the numerators and denominators: \(\frac{3}{3} \times \frac{12}{74} = \frac{3 \times 12}{3 \times 74} = \frac{36}{222}\) - Simplify the fraction: \(\frac{36}{222} = \frac{6}{37}\) 3. \(4\): - The result is already 4. Therefore, the expression that has a result equal to 1 is \(4\).