1. In the equation of a line, y=4x-3, the number -3 represents the________.
2. In the equation y=mx+b, the letter_________ represents the slope and the letter ________ represents the y- intercept.
3. Points M(2,-8) and N(0,-4) are on a line. The slope of the line is _______ and the y- intercept is _________. The equation of the line is _______.