How do i use a slope formula to find the slope of the line that passes thru 2 given points. then state whether the line is increasing decreasing, horizontal or vertical. ex: (1,5) (3,9)

Slope formula : slope = (y2 - y1) / (x2 - x1)
set 1 : (1,5)x1 = 1 and y1 = 5
set 2 : (3,9)...x2 = 3 and y2 = 9
now we sub into the formula
slope = (9 - 5) / (3 - 1) = 4/2 = 2

the slope 2 is increasing because it is positive. If the slope would have been negative, it would have been decreasing.

On ur 2 sets of points...if the x terms would have been the exact same number in both sets, then it would have been a vertical line. If the y's would have been the same, it would have been a horizontal line.