SOLUTION: A line passes through the points (0,-1) and (2,3). What is the equation for the line?

Algebra ->  Graphs -> SOLUTION: A line passes through the points (0,-1) and (2,3). What is the equation for the line?      Log On


   

Question 255704: A line passes through the points (0,-1) and (2,3). What is the equation for the line?
Answer by EMStelley(208) About Me  (Show Source):
You can put this solution on YOUR website!
The first step in finding the equation is to determine the slope. Remember that the slope of the line passing through (x1, y1) and (x2, y2) is:
m+=+%28y2+-+y1%29%2F%28x2+-+x1%29
So in our case we have:
m+=+%283+-+%28-1%29%29%2F%282+-+0%29+=+4%2F2+=+2
So our slope is m=2. Now, the equation for a line using the slope and one point is:
y - y1 = m(x - x1)
So using m=2 and (0, -1) we have
y - (-1) = 2(x - 0)
y + 1 = 2x
y = 2x-1