Irene R. answered 01/24/20
Senior Mechanical Engineer with 13+ years of Teaching Experience
The slope-intercept form of the equation of a line is : y = mx + b where m is the slope of the line and b is the y-intercept. You can determine the slope of the line using the two points given in the problem as follows:
The slope, m , will be (y2 - y1) / (x2 - x1).
For this problem, the slope, m, will be (-4 -10) / (6 - (-1)) OR -14/7
Also -14/7 is equivalent to -2 in simplest form. Therefore, the slope of the line is -2
Now to determine the y-intercept, b, use one of the points and the slope as follows (you can select either point ; I will use -1, 10):
y= mx + b
10 = -2 * -1 + b
10 = 2 + b
10 - 2 = 2 + b +-2
8 = b
Therefore, the equation of the line is: y = -2x + 8
You can always verify your equation by substituting the coordinates of one of the given points in the equation:
y = -2x + 8 USE ( 6, -4)
-4 = -2*6 + 8
-4 = -12 + 8