Talkin’ 2×2=5 Blues

Are we allowed to do talkin’ blues algebra proofs?
If NOT, maybe this is why — here’s one inspired by Lewis Carroll.
Goes a little like this:

And yes, there IS an error lurking somewhere in the algebra of this “proof”.
Can you spot it?

ALSO, if YOU can come up with a better rhyme for “polynomial expansion”, we’re all ears.

And while we’re at it, by the way, here are some references that crept in on page one:

• Lewis Carroll employs the transitive property (A.K.A. Euclid’s First Proposition) in his logical dialogue, What the Tortoise Said to Achilles … thus the tortoise.  [Read more about the dialogue @ wikipedia.org]
• “Two things equal to the same thing…” ~ Something about this statement sounded like an Abraham Lincoln speech, so as is our wont we went a’searchin’ … And it turns out Tony Kushner wrote this choice morsel of Euclid into a key scene of Spielberg’s “Lincoln” (2012).  So it’s not actually a speech of Lincoln’s, but we know Lincoln learnt his Euclid well, & may very well have thought along these lines.  (He would surely have seen the Euclid-style axiom-ism built into the opening sentence of the Declaration of Independence, don’t you think?)
  [Click here to read Jim Emerson’s perspective analysis of politics & geometry in Spielberg’s movie! >>]
• The bunny playing guitar and banjo is not a reference to anything, really.  We just like musical bunnies.

NEXT: Now with MUSIC! >>

AND SOON: How to make money off just this sort of shoddy math >>