Finding the equation of a straight line with only the y-intercept and one point.?

you can call it counting but its not really that you take six and find the difference the first one would be y=2/1x + 6 the other is y=10/4x -2 the number at the end is the y intercept and number over a number is the difference between the 2 points (the 2/1 and 10/4) and you styart out with y = every time