Answers

2015-08-27T19:59:36+08:00
   4/5 -3/10 + 3/10 - 5/6 + 8/20
= 4/5 - 5/6 + 8/20
= 24/30 - 25/30 + 8/20
= -1/30 + 8/20
= -2/60 + 24/60
= 22/60
= 11/30
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