Solve the equation. \[ -9 y-3 y=\frac{6}{7} \]

Step 1 ：Combine like terms on the left side of the equation to get \(-12y = \frac{6}{7}\).

Step 2 ：Divide both sides of the equation by -12 to isolate y: \(y = -\frac{6}{7} \div 12\).

Step 3 ：Simplify the right side of the equation to get the final solution: \(y = -0.0714285714285714\).

Step 4 ：Final Answer: The solution to the equation is \(\boxed{-0.0714285714285714}\).