Answers

2015-07-11T14:41:37+08:00
If you're adding positive and negative signs, you must change the sign of the larger number and subtract to get the answer. :)
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2015-07-11T19:57:46+08:00
1 + 1 = 2
1 - 1 = 0
- 1 - 1 = - 2
- 1 + 1 = 0
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