Answer:
This drawing should help a lot, and the way you solve the last one is you divide both sides by 2x making it an equation you can use to solve the graph.
Explanation:
remember, y=mx+b, m is the slope because the x is the ever increasing variable of the slope, and b is where you start the line on the y axis, so it makes this much easier knowing that the slope for a whole number, is just putting a 1 underneath it, and it applies to every number even negatives too.