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OG 11 Problem Solving #14

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OG 11 Problem Solving #14

by stacyp0220 » Tue Mar 31, 2009 4:03 pm
#14) Which of the following CANNOT be a value of 1 / x-1 ?

a) -1
b) 0
c) 2/3
d) 1
e) 2

i chose (d) because 1 / (1-1) = 1/ 0 = undefined

however, the answer in the OG is b?

can someone explain this?
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by VP_Jim » Tue Mar 31, 2009 9:33 pm
It's not asking for the value of x; it's asking what the RESULT of that expression cannot be.

It cannot be zero, since (1 / anything) won't equal zero.
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by BlueDragon2010 » Thu Apr 02, 2009 12:00 am
This is a longer way to solve, but you could set 1/x-1 equal to each answer choice until you find one choice that is a mathematical impossibility

B) 1/x-1 = 0 --> 1=0 Illogical.
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