Question 1101187

given that a+b=c, a+b=d and b=c+d, where d is a possible integer, what is the greatest value of a? 
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(1)  a+b = c
(2) a+b = d
Without going further, you should immediately see that these two equations tell you c=d.  
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(3) b=c+d (which means  b=2c=2d)

Plugging in "2c" for "b" in eq(1):
a + 2c  = c   —> a = -c (= -d)
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Ans:  <b> a = -c  (= -d) </b>
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