How can you tell if a point is on a line?

To determine if a point is on a line, you can substitute the coordinates of the point into the equation of the line. If the equation holds true after substitution, the point lies on the line. For example, for a line defined by (y = mx + b), if you plug in the x-coordinate of the point and the resulting y-value matches the y-coordinate of the point, then it is on the line. Otherwise, the point is not on the line.