Part a: the graph of which equation below is a horizontal line?
1) x + y =3
2) y = 3
3) x = 3
4) x/y = 3

part b: explain in 3-4 sentences why your equation in part a is a horizontal line. your answer should include at least 4 of the following words: x-coordinate, y-coordinate, ordered pair, slope, y-intercept, slope-intercept form