Finding the terminal points

The segment joining (1 -3) and (4 -6) is extended a distance equal to one sixth of its own length. find the terminal points.
How to solve this problem. I need the whole SOLUTION. THANKS

There are two possible extension points as shown. Use the following formulas to find these points:
x=x1+r(x2x1)

y=y1+r(y2y1)

Note:
(x1, y1) = (1, -3) and
(x2, y2) = (4, -6)

img_299.jpg

For extension point 1, use r = -1/6; and for extension point 2, use r = 7/6.

In reply to by Anonymous (not verified)

Consider the original line (green) to be composed of six parts so that extensions are 1 part each. From (1, -3) to Extension point 1 is -1 part and from (1, -3) to (4, 6) is 6 parts, hence, r = -1/6. Do similarly to Extension Point 2.