 Hello and welcome to the session. Let us discuss the following question. It says a line passes through x1, y1 and hk. If the slope of the line is m, show that k minus y1 is equal to m into h minus x1. Now the slope of the line joining the points say x1, y1 and x2, y2 is given by y2 minus y1 upon x2 minus x1. So this is the key idea. Let us now proceed on with the solution. We are given two points as x1, y1 and hk. Now the slope of line joining a and b is given to be m and the slope joining these points is given by k minus y1 upon h minus x1. And this is equal to m and this implies k minus y1 is equal to m into h minus x1. Hence we have proved that k minus y1 is equal to m into h minus x1. So this completes the question. Hope you will be able to solve more such problems. Take care and bye.