There are two equations hidden in the language here:
a + b = 56 and a - b = 10.
if you do (a+b) + (a-b) then you get:
(a+b) + (a-b) = 66 = a + b + a - b
The b's cancel, so you get 2a = 66, which means a = 33. You can use this to solve for b in one of the above equations by plugging in a = 33 and figuring out what b has to be. Then you will have your two numbers.
