Modeling proportional relationships with graphs is an exciting adventure!

1. Understanding Slopes:
   A straight line that goes through the point (0,0) shows direct variation. Here, the slope, which is how steep the line is, represents the constant of proportionality, called $k$.

2. Linear Equations:
   We can represent these relationships with the equation $y = kx$. This means that when $x$ gets bigger, $y$ also gets bigger in a similar way!

3. Interpreting Graphs:
   It's important to look closely at the graph to see how changes in one part affect the other part. It's all about these cool relationships!

Let’s explore these graphs to discover their secrets!