Answers

2014-12-02T20:51:02+08:00
X + y = 58     -----equation 1
x - y = 20     -----equation 2
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Add equations 1 and 2
    x  + y = 58
+  x  - y = 20
    2x   = 78
      x = 39
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Substitute x=39 to equation 1
x + y = 58
y = 58 - x
y = 58 - 39
y = 19
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Therefore the ordered pair is (39,19).

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