Hi Connie. You are right, these linked expressions do not need to follow the special margins rule. If there is text after the numbers 1. and 2., then yes these should be formatted as displayed expressions, starting the anchor in cell 5 and placing all runovers in cell 7. If there is no text after the numbers 1. and 2., as shown in the example you attached, then I would begin each anchor on the same line as the identifier, placing all runovers in cell 3.
When a link needs to be divided within a series of complicated linked expressions like these, the first rule of thumb for clarity is to start a new line with each link. In these examples, that means at each baseline equals sign. I like to do that even with the final link, which tends to be short. Starting each link on a new line gives clarity to the progression.
To divide a long link, the first priority is keeping the enclosed portions together on the same line. Beyond that, go as far as you can and then divide at one of the indicators from the priority list. In number 1 and number 2, this turns out to be a superscript indicator.
I would not divide again before the dy. An implied operation sign is not on the list. I see no reason to break before a factor when it will fit on the line.
In number 3, I would go ahead and transcribe the subscript (x = 1/2 y) since it fits on the line with that closing bracket. Then start the new line with the superscript indicator.
Hope this helps!