3. \( \left\{\begin{array}{l}6 x=24 \\ y=-x-3\end{array}\right. \)

To solve the first equation, \(6x = 24\), divide both sides by 6, giving \(x = 4\). Now, substitute this value into the second equation \(y = -x - 3\). Plugging in \(x = 4\), you get \(y = -4 - 3\), which simplifies to \(y = -7\). Therefore, the solution to the system of equations is \( (4, -7) \). To visualize how systems of equations work, consider them as intersecting lines on a graph. Each equation represents a line, and their point of intersection (in this case, \( (4, -7) \)) is the solution. Graphing is a great way to confirm your answer and see the relationships between the equations.