How do you write the equation of a line if you have two points? Please use detail and give step by step instructions: trying to study for a test and I don't understand this concept.
figure the slope m between the two points
pick one of the points and call its coordinates (h,k)
Then, since the slope never changes, the slope between (x,y) and (h,k) is the same for any (x,y) on the line.
So, (y-k)/(x-h) = m, the slope between the two given points. This is usually written as
y-k = m(x-h)