Derek McMillan Posted September 13, 2004 This is referred to as a chestnut but it amuses me. x = 1 Therefore: x² = x x² - 1 = x -1 Factorising x² - 1 we get (x - 1)(x + 1) = x - 1 Dividing both sides by (x - 1) we get: x + 1 = 1 Substituting 1 for x we get: 2 = 1 Try this on a year 9 class last thing on a Friday afternoon. I dare you. Share this post Link to post Share on other sites