Find the value of c such that the three points (5,5), (3,1), and (-6,c) lie on the same line. Note: Three points are on the same line if the slope of the line through any two points is always the same.
Slope, m, between the first two points (y1-y2)/(x1-x2) = 4/2 = 2
slope between the next two points is also = 2 so (1-c)/(3--6) = 2
1-c = 18
c = -17