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Must be true --> a3b = ab3

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Must be true --> a3b = ab3

by Vemuri » Wed Apr 15, 2009 9:39 am
If ab ≠ 0 and a^3b = ab^3, then which of the following must be true?

a = b
a = –b
ab = 1

A. None
B. I only
C. III only
D. I and III only
E. I, II, and III

OA is A. Please explain with reasoning
Last edited by Vemuri on Thu Apr 16, 2009 4:21 am, edited 1 time in total.
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by scoobydooby » Wed Apr 15, 2009 9:56 am
if a3b=ab3, then b must be 3.
the number must be of the form a33. a can take any value.

not necessary that a must be =b, -b or ab=1.
hence, A
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by vittalgmat » Wed Apr 15, 2009 11:52 am
I dint even undersand the Question.
@Vemuri,
does a3b mean a-cubed * b?
and does ab3 mean a * b-cubed ?
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by Vemuri » Thu Apr 16, 2009 4:20 am
vittalgmat wrote:I dint even undersand the Question.
@Vemuri,
does a3b mean a-cubed * b?
and does ab3 mean a * b-cubed ?
Oppsss...sorry guys. I copy pasted the question from a website & looks like the some characters went missing. I have corrected my original post.

Sorry for the confusion. I am generally careful when posting the questions, missed it out this time :-)
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