Mathematical Proof That 2 = 1
Try this one
out - see if you can find the hole here!
(Don't scroll down until you've given it a good shot ...)
Initial supposition x = y
Multiply both sides by x xx = xy
Subtract y squared from both sides xx - yy = xy - yy
Factor both sides (x + y)(x - y) = y(x - y)
Divide both sides by (x - y) x + y = y
Substitute y for x, based on initial supposition y + y = y
Replace y with any number (eg. 1) 1 + 1 = 1 or 2 = 1
Scroll down to see the 'flaw'.....
The step that divides through by (x - y) is effectively dividing by zero, based on the
initial supposition. That invalidates the subsequent results.