To estimate the values of x when y = 4 using the graph of y = x² - x, you would need to locate the point on the y-axis where y = 4 and draw a horizontal line across the graph until it intersects with the curve of y = x² - x. The x-coordinates of these intersection points are the estimated values of x when y = 4. However, since I don’t have access to the graph you mentioned, I can’t provide you with an estimate.