How to Write a slope intercept equation for a line on a graph

A topic which is taught during school days: The slope - intercept equation of a line in a 2 dimensional space. As explained in the video, it is written in the following form: y = mx + b Here the x and y symbols represent the co-ordinate axes, m represents the slope of the line which is nothing but the ratio of y upon x (in equation form represented as tan(A) = (y/x)) and the symbol b represents the distance from the origin, at which the line intersects with the y axis. The derivation of the equation from a given line is explained in the video.