The image contains a mathematical expression that reads as follows:

$\left( Z^+ + \varepsilon^-\right) \left( Z^- - \varepsilon^-\right) \quad (q)$

It seems to involve complex notation, but I would need more information on the context in order to provide a detailed explanation or solution. However, this appears to be an algebraic expression that could potentially be simplified.

Would you like me to attempt simplifying it or explore a different approach?

Here are some questions to expand on the information:

1. What do the variables $Z$ and $\varepsilon$ represent?
2. Are you working on a physics or mathematical problem that involves specific interpretations of these symbols?
3. Would you like me to simplify this expression assuming they are algebraic variables?
4. Do you have more context about the part labeled as $q$?
5. Should I interpret the superscripts $+$ and $-$ in a specific way (like indicating charges or directional components)?

Tip: When working with variables that have subscripts or superscripts, it's important to understand if they are just notation or have a deeper meaning within a specific context (such as quantum physics or signal processing).