Doubt in Transformation of graphs.

Hello team,
I hope you are keeping well,
Just one thing I found while doing the course of probability that the transformation concepts have been reversed.
Its in the Section 5 of probability 1st lecture.
The lecture shows when we add something to the input variable the curve shifts to the right, and when we subtract something from the input variable the curve shifts to the left.
However that had to be reversed, like adding something shifts the curve to the left and subtracting shifts the curve to the right.
I am attaching an ss for the same.

You may correct the error, which will help the other students.
Keep up the good work,
Kind Regards
Yuvraj.