Complete the equation of the line through (1,4) (2,2)

The slope- intercept form of the equation of a line is : y = mx + b

The slope is represented by m and the y-intercept is represented by b.

You can use the coordinates of the two points to find the slope:

m = (y 2 - y 1)

 (x 2 - x 1)

For this problem:

m =   (4 - 2 ) =   2  

(1 - 2)     -1

To determine the y-intercept , substitute the coordinates of either point into the slope-intercept equation using a slope of -2:

y = mx + b

y = -2 • x + b

Using (1,4):

4 = -2 • 1 + b

4 = -2 + b

b = 6

The equation of the line will be :  y = -2•x + 6