Just off of what you asked, assuming that y=x, Take five numbers, lets say 1, 2, 3, 4, and 5, and make these x. And because y=x, you will have the same number as is in the x column. Since earlier the numbers for x were 1, 2, 3, 4 and 5, y is also 1, 2, 3, 4, and 5.