Question 292931: If a < 0 < b, then which of the following expressions is equal to
|a - b| + |a + b| ?
(A) 2a + 2b (B) 2a - 2b (C) 2a (D) 4b (E) 0
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! If a < 0 < b, then which of the following expressions is equal to
|a - b| + |a + b| ?
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Since b is greater than a, b-a>0 and a-b is a negative number.
Therefore |a-b| = -(a-b) = b-a
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Also, even though b is greater than a, we don't
know if a+b is positive or negative (b could be 1 and a could be -1000)
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So |a+b| = a+b or it might equal -(a+b)
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If |a+b| = a+b the problem becomes (b-a)+(a+b) = 2b
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If |a+b| = -(a+b) the problem becomes (b-a)-(a+b) = -2a+2b
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I don't like any of the answers listed below.
Cheers,
Stan H.
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(A) 2a + 2b (B) 2a - 2b (C) 2a (D) 4b (E) 0
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