Exploring m and c in the gradient intercept form of a straight line

The document shows an example of finding the slope and y-intercept of a line using two points. It gives the general equation of a line as y = mx + c and shows the specific line with m = -8 and c = 11. It then generates two points (-3, 35) and (-3, 35) on the line and shows that using those points in the slope formula m = (y2 - y1) / (x2 - x1) results in division by zero since the x-values are the same.