Answer:
Table 1 (leftmost)
Explanation:
A linear function has a common difference between all of the x-values. This means that all the x-values change by the same amount relative to the change in y. In this case, the x-value increases by 1/2 every time that y increases by 1. The other tables do not work because their change is inconsistent. There is no number being added each time. Therefore, they are not linear. If you were to graph these tables, only table 1 would make a straight line.