You can work out which points lie on a line outside the coordinate system

If you extend the line through A and B to the right, it

will pass through a point with first coordinate 30.

What is the second coordinate?

2 steps to the right on the horizontal axis is 3

steps up on the vertical axis. So 1 step to the right

on the horizontal axis is 1.5 steps up on the vertical

axis. From point (1, 1) you have to go 29 steps to the

right, so you have to go 29 x 1.5 = 43.5 steps up, so

you will be at point (30, 44.5).

The second coordinate is 44.5