From the table provided, we see that each value of $y$ matches the corresponding value of $x$. Specifically:

• When $x = -18$, $y = -18$
• When $x = -12$, $y = -12$
• When $x = -6$, $y = -6$
• When $x = 0$, $y = 0$

This indicates a direct relationship where $y = x$. Therefore, the equation describing this relationship is:

$y = x$

Would you like a further breakdown of this relationship or have any questions about it?

Here are some related questions for further exploration:

1. What would $y$ be if $x = 10$ using the equation $y = x$?
2. How would the equation change if each $y$-value were double the $x$-value?
3. What is the slope of the line represented by this equation?
4. How can you graph this equation on a coordinate plane?
5. How would the equation change if all $y$-values were shifted up by 5?

Tip: Recognizing a simple linear relationship in a table of values helps to quickly determine the equation that describes it.