Given the coordinates of the points of a line on the circle A(1.-1) and B(8, 6). To get the equation of the line, we will need to get the slope and the intercept of the line.
The standarad equation of a line is expressed as y = mx+c
m is the slope
c is the intercept
m = y2-y1/x2-x1
Substitute the coordnate points into the formula;
m = 6-(-1)/8-1
m = 6+1/7
m = 7/7
m = 1
Next is to get the intercept of the line. You can do this ny substituting m = 1 any of the points into the equation ofa line and calculate c as shown
y = mx+c
Using point (1, -1)
-1 = 1(1)+c
-1 = 1 + c
c = -1-1
c = -2
Substitute m =1 and c = -2 into the formula to the required equation as shown;
y = 1x+ (-2)
y = x - 2
Hence the equation of the line that goes through points A and B​ is y = x-2