If x and y both equal one, then the following is true
2 * (x^2 - y^2) = 0
and so is the following
5 * (x - y) = 0
thus, logically they equal each other
2 * (x^2 - y^2) = 5 * (x - y)
now, this is where we lose people. since (x^2 - y^2) really stands for
(x - y)(x + y), then we can divide (x - y) out each side of the equation
2 * (x + y) = 5 * 1
plug in the numbers, 2 * 2 = 5
Suck that, biznatch.