Answers

2014-11-17T20:50:20+08:00
(39+45)-x=37
84-x=37
-x=-47
x=47

You subtract 47.
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2014-11-17T20:51:35+08:00
39 + 45 = 84
37 = 84 -x
x = 84-37
x = 47
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