[glatt]

Originally Posted by tw

(a+b)(a-b) = b (a-b)
a+b = b

To get from (a+b)(a-b) = b (a-b)
to
a+b = b
you must divide each side by (a-b). That's great, except...

since a=b, then (a-b) = (a-a) = 0

Only Chuck Norris can divide by zero.