[racket] stumped by a little macro exercise

Unfortunately, each of those mtc's is different.

Let me suggest you do this instead.  Put the expression you typed at
the > prompt in the Definitions window, and click on the Macro Stepper
button.  Step twice.  The coloring is extremely significant (the only
good use of syntax coloring I've seen in my life) -- it represents the
hygienic macro expansion algorithm.

If this coloring doesn't make sense to you, then you might want to
write a much simpler macro just to explore how hygiene works.

If this coloring does make sense to you, then you can go back to
understanding its implication for your macro.

Shriram