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
