Verified answer

Point 1 = ( 2, 6 )

Point 2 = ( 6, 12 )

this is the formula to use m = (y2 - y1) / (x2 - x1)

In your case y2 = 12 , y1 = 6 , x2 = 6 , x1 = 2

substitute and get m = 3/2

for an explanation, I suggest you see this video

http://youtu.be/Tt0BjZT_qNg

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