How do you draw a straight-line graph using the 'table of 3 values' method?

First create your table of 3 values. It doesn't really matter what values of x you pick but for ease I would typically pick x = 0, x = 1 and x = 2. Then you need to substitute each of these values of x into the equation of the line to find the corresponding y values. Then each of these pairs of x and y values are co-ordinates you can plot and then draw a straight line through them.

Example y = 3x - 5

x = 0 y = 3(0) - 5 = -5

x = 1 y = 3(1) - 5 = -2

x = 2 y = 3(2) - 5 = 1

So the co-ordinates of the 3 points would be (0, -5), (1, -2) and (2, 1).