Answer:
For question 2 the slope is 1. So what you do is get the points you need to put on the graph and move them up one. Like how you did on question 1.
(0.5, 5) (1, 10) (1.5, 15) (2, 20) (2.5, 25)
Question 3 is the same thing but the slope is now 2. Then you would have to pin the points as...
(1, 2) (2, 4) (3, 6) (4, 8) (5, 10)
Hope this helped :)