Exercise 5 Page 156

Let's begin by recalling that a linear function has constant rate of change. To determine whether the given table represents a linear function, we will check if $x$ and $y$ change by the same quantity over equal intervals.

We can see that, as $x$ increases by $5,$ $y$ decreases by $3.$ This means that the rate of change is constant. Therefore, the given table represents a linear function.