Let's plot the points (1,3) and (4, 6), as follows:
As you can see, we have:
x = 1, y = 3 as the first point we know.
x = 4, y = 6 as the second point we know.
We can replace y, with x + 2 (3 - 1 or 6 - 4),, therefore the equation of this line is:
x + 2 = y or x = y - 2 Any of these equations will solve the question A.