* Lets say y = x * Multiply through by x xy = x2 * Subtract y2 from each side xy - y2 = x2 - y2 * Factor each side y(x-y) = (x+y)(x-y) * Divide both sides by (x-y) y = x+y * Divide both sides by y y/y = x/y + y/y * And so... 1 = x/y + 1 * Since x=y, x/y = 1 1 = 1 + 1 * And so... 1 = 2