Rate Of Change And Slope

by Mary

(-2,-5)(7,8)Is the answer negative 3 over 21 which is -7?

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Dec 13, 2014
by: Anonymous

(6,-9) and (-3,-8). Find the slope of the line through the pair of points

May 22, 2014
Good Job
by: Anonymous


Oct 09, 2010
Rate of Change and Slope
by: Karin

Hi Mary,

If you want to find the slope of a line that passes through two points, you must use the equation:

y(sub2) - y(sub1) / x(sub2) - x(sub1)

(In this application, I cannot type subscripts. Therefore, when I write (sub2) that means the subscript 2.)

Let's talk about what that formula means.

You have two points. Point 1 is (-2, -5) and Point 2 is (7,8)

When I use (sub1) this refers to point 1. When I use (sub2) this refers to point 2.

So, basically we are going to subtract the y coordinate from the 2nd point and the y coordinate from the first point. We will do the same with the x coordinates and divide the two numbers.

Take a look:

(-2, -5) (7,8)

Step 1: Subtract the y-coordinates from each point.

8 - (-5) = 13

Step 2: Subtract the x-coordinates from each point.

7 - (-2) = 9

Now we will divide.


This is the final answer. The slope or rate of change is 13/9.

Take a look at the lesson on website. It may help you understand this concept.


I hope this helps,

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