The points 6,4 and 9,r lie on a line with slope 3. Find the missing coordinate r.
Slope = (y2 - y1)/(x2 - x1)
Plugging in our numbers, we get:
3 = (r - 4)/(9 - 6)
3 = (r - 4)/3
Cross multiply:
r - 4 = 9
Add 4 to each side:
r = 13
Slope = (y2 - y1)/(x2 - x1)
Plugging in our numbers, we get:
3 = (r - 4)/(9 - 6)
3 = (r - 4)/3
Cross multiply:
r - 4 = 9
Add 4 to each side:
r = 13