Answer:
Zero
Explanation:
Average rate of change can also be called as gradient or change in the respective variable , in this case we need the average rate of change of y which has the function y = -7
Since this is a linear function and if we draw the graph of y = -7 the graph would be parallel to the x-axis, and any line parallel to the x-axis has slope of zero , hence the average rate of change of the function y = -7 is zero