Final answer:
The slope of line r is -3/4.
Step-by-step explanation:
To find the slope of line r, we need to use the slope formula. The slope formula states that the slope (m) of a line passing through two points (x1, y1) and (x2, y2) is given by the equation:
m = (y2 - y1) / (x2 - x1)
Given the points (3, 10) and (7, 7), we can substitute the values into the formula:
m = (7 - 10) / (7 - 3)
m = -3 / 4
Therefore, the slope of line r is -3/4.