Explanation: Since the sum of the two numbers is ten, x + y = 10
Also, since the difference of the two numbers is two, then x - y = 2
Since x - y = 2, another way to write that is x = y + 2 and since x is exactly the same as y + 2, we can plug in "y + 2" in place of x in the first equation (x + y = 10) to get (y + 2) + y = 10. Then we solve this equation by combining like-terms.