1) Pick 3 points and plot their values - the resulting line will go through all of them and be the right line

f(x) = 3x-1

f(-1) = -4

f(0) = -1

f(1) = 2

2) Start with f(0) and find that [f(0) = -1]. From there go up 3 for every 1 to the right and down 3 for every one to the left