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.