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# The sum of the possible values of X in the equation |X + 7| + |X – 8|

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Re: The sum of the possible values of X in the equation |X + 7| + |X – 8| [#permalink]
3
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Ans :B

Both terms either can be +ve or - ve
If +ve X=17/2
If - ve X=-15/2
Sum =1

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Re: The sum of the possible values of X in the equation |X + 7| + |X – 8| [#permalink]
Solving this question on number line is much easier and accurate enough.
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Re: The sum of the possible values of X in the equation |X + 7| + |X – 8| [#permalink]
1
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Both positive
X+7+X-8=16
X=8.5

BOTH negative
-X-7-X+8=16
X=-7.5

ADDING BOTH VALUE WILL BE 1
ANSWER IS B

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Re: The sum of the possible values of X in the equation |X + 7| + |X – 8| [#permalink]
GMATinsight wrote:
The sum of the possible values of X in the equation |X + 7| + |X – 8| = 16 is:

A. 0
B. 1
C. 2
D. 3
E. None of the above

critical points: ...(neg,neg)...-7...(pos,neg)...8..(pos,pos)..

x>=8: x+7+x-8=16, x=8.5
-7<=x<8: x+7-x+8=16, 15=16 invalid
x<-7: -x-7-x+8=18, x=-7.5

sum 8.5+-7.5=1

ans (B)
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Re: The sum of the possible values of X in the equation |X + 7| + |X – 8| [#permalink]
Hi , is there any generic method to solve such questions?
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Re: The sum of the possible values of X in the equation |X + 7| + |X 8| [#permalink]
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Re: The sum of the possible values of X in the equation |X + 7| + |X 8| [#permalink]
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