The slope of a line is calculated as the change in the y-coordinates (rise) divided by the change in the x-coordinates (run). Using the coordinates (9, 10) and (7, 2), we can calculate the slope as:
(10 - 2) / (9 - 7) = 8 / 2 = 4
So, the slope through the line of (9, 10) and (7, 2) is 4.