Still having trouble with comparing equal things

Question

I just can't seem to grasp the whole thing of comparing equal things for some reason. I don't know why, but I need help, because I have a test to do next Monday, and I am sure that there will be a section on comparing equal things.

Answer 1

Have a look here

And here

These are two of the many "reference" articles on SD.

For a reason I don't understand they are almost "hidden".