Finding the Equation of a Line from Two Points

Find the midpoint

Determine the slope

Graph the points

Calculate the y-intercept

By finding the midpoint of the line

By calculating the change in y over the change in x

By subtracting the y-coordinates

By adding the x-coordinates

1

-1

2

-2

y = -2x + 7

y = 2x - 7

y = -2x - 7

y = 2x + 7

Because the slope might be zero

Because the points might not be integers

Because the graph might not be available

Because the graph might be too complex

(y1 - y2) / (x1 - x2)

(x2 - x1) / (y2 - y1)

(y2 - y1) / (x2 - x1)

(x1 - x2) / (y1 - y2)

The points are on the y-axis

The points are different

The points are on the x-axis

The points are the same

0

7

-7

2

By graphing the line

By finding the midpoint

By using the slope formula

By substituting a point into the equation

Because the line is finite

Because the slope changes

Because the y-intercept changes

Because the line represents an infinite set of points