Question

The graph represents the wind speed of a weak hurricane in the hours after making landfall. Image below

Answer 1

Use the points I circled on the graph to form the equation of this line.

Point 1 : (2,70)
Point 2 : (10,50)

For instructions on how to form a line using two points, use this link:

http://www.mathsisfun.com/algebra/line-equation-2points.html

Answer 2

In short, you will find the slope using the slope formula, Slope m = change in y / change in x = (yA - yB) / (xA - xB). Then, you will use the point-slope equation, y - y1 = m(x - x1), plugging in your slope and one of your points.

Answer 3

Good, yes, your slope is -2.5. Now, plug that in to the point-slope equation, along with one of your points, and solve for y.

Answer 4

In the point-slope equation, the point you choose is (x1,y1). It could be either (2,70) or (10,50), it doesn't matter; all that matters is you choose one point that is on the line. Leave x and y as variables. Solve for y.