Whenever you're subtracting a negative number, that's the EXACT same thing as adding that number. For example:

32 - (-7)

This is the equivalent of:

32 + 7

Which equals to:

39

The following equations also work:

27 - (-13) = 27 + 13 = 40

108 - (-248) = 108 + 248 = 356

36 - (-62) = 36 + 62 = 98

And so on.