Find the sum or difference of the following integers.
1. (+54) - (+45) = 6. (+124) - (+325) =
2. (-10) + (+15) = 7. (-228) + (+144) =
3. (+35) - (-18) = 8. (+864) - (213) =
4. (-26) + (-39) = 9. (-1000) + (-1000) =
5. (+44) - (-44) = 10. (+679) - (+165) =