It looks like you're presenting a function \( f(x) = 2.5x \). This is a linear function where:
- The slope (or coefficient of \( x \)) is 2.5, which indicates that for each unit increase in \( x \), the value of \( f(x) \) increases by 2.5.
- There is no constant term added (i.e., there is no \( + b \) term), meaning it passes through the origin (0,0).
If you have any specific questions or if you would like more information about this function, such as its graph, intercepts, or applications, please let me know!