1. Let's clarify the problem: We have an expression where $6y$ is also in the denominator. 2. Suppose the expression is $\frac{3x}{6y}$ or similar, where both numerator and denominator are given. 3. The general rule for fractions is that the denominator cannot be zero, so $6y \neq 0$ which means $y \neq 0$. 4. To simplify $\frac{3x}{6y}$, factor numerator and denominator: $$\frac{3x}{6y} = \frac{3x}{6y} = \frac{3x}{6y}$$ 5. Since $6 = 3 \times 2$, rewrite denominator: $$\frac{3x}{3 \times 2 \times y}$$ 6. Cancel common factor 3: $$\frac{x}{2y}$$ 7. So the simplified form is $\frac{x}{2y}$, valid for $y \neq 0$. 8. If your expression is different, please provide the full expression for precise help.