(no subject)

[plonq]

Assume         a = b
therefore      a - b = 0
additionally  2a - 2b = 0
therefore      a - b = 2a - 2b, or
             1(a - b) = 2(a - b)


Now if we factor out the (a - b) from this equation...


                 1          1
             1(a - b) = 2(a - b)
               -----------------
                   (a - b)
                      1

Ergo           1 = 2 

Most people spot the fallacy right away, but it's surprising how many people I've caught with this one.

Comments

[plonq.livejournal.com]

his equation is undefined as you cannot divide by zero

Puh. Certainly you can divide by zero. A real-life example is when there are two slices of pizza left, and we're trying to decide which slice is yours... unless you go all spastic and lick your hands and paw the pieces before we can come to an equitable division I mean, then things get a bit undefined again.

[pierrekrahn.livejournal.com]

LOL

Your saliva tastes good.