For the linear system given by the equations \( y = -x + 6 \) and \( 3x + 3y = 18 \), we want to determine whether the system has an infinite number of solutions.
First, let's rewrite the second equation in slope-intercept form to understand its relationship to the first equation:
\[ 3x + 3y = 18 \]
Dividing the entire equation by 3 gives:
\[ x + y = 6 \ y = -x + 6 \]
Now we see that both equations are identical since they represent the same line: \( y = -x + 6 \).
When two linear equations represent the same line, they have an infinite number of solutions because any point on that line satisfies both equations.
Now, let’s review the graphs described:
- Graph A: Shows two parallel lines.
- Graph B: Shows two intersecting lines.
- Graph C: Shows a single line.
- Graph D: Shows another single line.
The graph that depicts the infinite number of solutions is one where both equations are represented as the same line, which corresponds to a single line being plotted.
Therefore, the correct option for a graph that shows the linear system has an infinite number of solutions is one that shows a single line, which aligns with either Graph C or Graph D based on their descriptions. Since we need the graph representing both the equations as one, the graph that provides this is the one depicting the line \( y = -x + 6 \).
If you need to choose from the options listed, it would be the graph depicting the single line \( y = -x + 6 \).