Subtracting a negative number is the same as adding the positive.
The answer may be positive or negative depending on the size of the numbers.
Examples
5 - -11 = 5 + 11 = 16
-11 - -3 = -11 + 3 = -8
Remember
-11 + 3
is the same as
3 + -11
which is the same as
3 - 11
which is -8
On to the questions!