SOLUTION: What is the slope of line that passes through the points (7,-2) and (-1,-5)?

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Question 566107: What is the slope of line that passes through the points (7,-2) and (-1,-5)?
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
There are two methods.  By graph, and by formula.  Plot the two points:

(7,-2) and (-1,-5)



Draw a line through them



Draw a green run and a red rise:



Count how many units the green run is long:



So we see that the run is 8 units ling.

Next, count how many units the red rise is long:



So we see that the rise is 3 units long.

To get the slope we put the rise over the run, like this:

slope = %28rise%29%2F%28run%29 = 3%2F8

That's the answer.

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Method 2: by the slope formula
 
m = %28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 with (x1, y1) = (7,-2) and (x2, y2) = (-1,-5)

m = %28%28-5%29-%28-2%29%29%2F%28%28-1%29-%287%29%29 = %28-5%2B2%29%2F%28-1-7%29 = %28-3%29%2F%28-8%29 = 3%2F8

Even if you use the slope formula, you must realize that what you actually
have is a measurement of the steepness of the line that connects the two
points, and not just a number to put on a test so the teacher will mark it
correct. :)

Edwin