Answer:
The unit rate is 3.
Explanation:
The unit rate is the slope of the line on the graph. The slope of the line on the graph will be the coefficient of x in the equation, so you don't really need to make the graph to find the unit rate.
To make a graph useful for finding the unit rate, it is convenient to choose x-values that are 1 unit apart.
For graphing, it is often useful to choose x=0 as a place to start. Here, that means ...
... y = 3·0 = 0 . . . . . one point on the graph is (x, y) = (0, 0)
Choosing x to be 1 unit from there, we have ...
... y = 3·1 = 3 . . . . . another point on the graph is (x, y) = (1, 3)
Now, we can see that a change in x of 1 unit has produced a change in y of 3 units. The unit rate is ...
... unit rate = slope = (change in y)/(change in x) = 3/1 = 3