How to make an infinitely long line from two points?

Question

Canvas

There are two points. A line is drawn on them on the coordinate system.
You need to make sure that these lines turn into straight lines. Tobish, lines without beginning and end, but to pass through these points.

Here is a picture, there are 3 lines. They need to overlap with each other.

Answer 1

1) get the equation of a straight line by two points (it’s easy to google), how to do it can be found here www.math.by/geometry/eqline.html
2) substitute the coordinates of the canvas borders into the equation - you get points lying simultaneously on the borders and on the straight lines
3) connect them with segments