So I was actually looking up math jokes to reply to Aviva's post and I came across this "proof":

Theorem: 3=4

Proof:

Suppose: a + b = c

This can also be written as: 4a - 3a + 4b - 3b = 4c - 3c

Reorganize to get: 4a + 4b - 4c = 3a + 3b - 3c

Separate the constants: 4 * (a+b-c) = 3 * (a+b-c)

Now if we remove the same term left and right, we end up with 4 = 3.

This just made me wonder why we can create a proof for something that isn't true. It makes me think of how lawyers can sometimes "prove" the innocence of their client/ conviction of the opposing client. I just thought this was kind of interesting and wanted to share…any thoughts?