Find x-intercept and y-intercept then you can draw the graph.
For example, the first question.
To find the y-intercept, x = 0
So substitute x = 0 in the equation.
[Note]: You don't need to find the y-intercept, because from,
a is slope and b is y-intercept, you know b then you know y-intercept. For example b = 2 then y-intercept is at 2.
To find the x-intercept, y = 0
Therefore, y-intercept = 2 and x-intercept = 2/3
(Try do another problems, just do the same. When you want to find the y-intercept, just look at the value of b or substitute x = 0 and When you want to find the x-intercept, just substitute y = 0 then solve for x.)