Simplify. Express your answer using positive exponents. \( \frac{3 y z}{\left(3 y z^{3}\right)(y z)} \)

To simplify the expression \( \frac{3 y z}{\left(3 y z^{3}\right)(y z)} \), we start by simplifying the denominator. The denominator can be rewritten as: \[ 3 y z^{3} \cdot y z = 3 y^2 z^{4} \] So, our expression now looks like this: \[ \frac{3 y z}{3 y^2 z^4} \] Now, we can cancel the \(3\) in the numerator and denominator: \[ \frac{y z}{y^2 z^4} \] Next, we can simplify \(y\) and \(z\) using the property of exponents: \[ \frac{y}{y^2} = y^{1 - 2} = y^{-1} \quad \text{and} \quad \frac{z}{z^4} = z^{1 - 4} = z^{-3} \] Putting it all together, we get: \[ y^{-1} z^{-3} = \frac{1}{y z^{3}} \] Thus, the simplified expression using positive exponents is: \[ \frac{1}{y z^{3}} \]