(z-6)•3/7=3

To solve the equation \((z - 6) \cdot \frac{3}{7} = 3\), follow these steps:

1. Multiply both sides by \(\frac{7}{3}\) to eliminate the fraction:

   \[ z - 6 = 3 \cdot \frac{7}{3} \]

   This simplifies to:

   \[ z - 6 = 7 \]

2. Add 6 to both sides to solve for \(z\):

   \[ z = 7 + 6 \]

   So:

   \[ z = 13 \]

The solution is \(z = 13\).