We can solve this by setting up a system of equations. x and y will represent the two numbers.
x+y = 12
x-y = -2
Personally, I'm going to solve the system by solving one of the equations for x and substituting it into the other one.
x = 12-y
12-y-y = -2
12-2y = -2
-2y = -14
y = 7
Now find the other number by plugging 7 in for y in one of the equations.
x+7 = 12
x = 5
OR
x-7 = -2
x = 5
So, the two numbers are 5 and 7.
