X+y=k
x-y=k
The solution of the system shown is
O (OK)
O (0,0)
O (k, O)

 (0,0)

Step-by-step explanation:

The only integer"s" that both add and subtract to the same value are 0 "and" 0.  Properly stated, the only integer that can be added to itself and subtracted from itself with the same outcome is 0.

Of course, k will also be 0

So this system of equation works out to be

0 + 0 = 0

0 - 0 = 0

-18 degrees is the answer : )