1. The problem asks: What is the rule? 2. In mathematics, a "rule" often refers to a formula or a function that describes a relationship between variables. 3. For example, a rule can be expressed as $y = f(x)$, where $y$ depends on $x$. 4. Rules can be linear, quadratic, exponential, or any other type depending on the context. 5. To identify or write a rule, you need to understand the pattern or relationship between inputs and outputs. 6. Without more context, the general rule is: $$\text{Rule: } y = f(x)$$ which means $y$ is a function of $x$. 7. If you provide a specific problem or pattern, I can help find the exact rule.