In this video the instructor shows how to write a linear equation. If you need to find the equation of a line that passes through the two given points then you need to find the linear equation of that line. The first step is to find the slope of the line that passes through these points. The slope can be calculated by finding the ratio of the difference of y coordinates to the difference of the x coordinates i.e. the change in y up on the change in x. Now substitute the value of slope and any of the two points in the slope-equation formula and simplify it to obtain the equation of the line. This line is a linear equation which represents the required line. This video shows how to write linear equations of lines.