Both Diego and Mai are interpreting the said graphs (please see attached) in terms of which are Negative, Positive, or neutral.
When you want to interpret a linear equation in relation to a graph, it is important to note that two factors are critical:
If the slope of the line rises from left to right, it is Positive; If it falls from left to right, it is negative, and if it remains on the same line across, but above the y-axis, then it is constant but above zero.
Therefore, in the order they have been arranged, the first graph is negative because its last value falls below the y axis, the second is above the y-axis but constant at a level above zero, while the third has its values increasing from left to right above the y-axis.
See the link below for more about Linear Graphs:
https://brainly.com/question/7040405