Answer:
-9
Step-by-step explanation:
Slope = rise/run = (y1 - y2)/(x1 - x2)
Therefore:
Slope = (7 - (-9))/(-5 - w)
4 = (7 + 9)/(-5 - w)
4(-5 - w) = 16
-20 - 4w = 16
4w = -20 - 16
4w = -36
w = -36/4
w = -9