x and y are positive integers.if [5^x]-[5^y]=[2^(y-1)][5^x] , what is the value of xy?
(A) 48
(B) 36
(C) 24
(D) 18
(E) 12--ans
Please explain
corrected...sorry for the misstake.
please provide the explanation...
Exponent algebra
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Last edited by ash_maverick on Thu Mar 01, 2007 11:32 am, edited 2 times in total.
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Please post the source of your question.
I'm guessing the word missing here is "consecutive" positive integers,
in which case only 3*4 = 12 would make the cut. Else, it would be impossible to find out xy from just "positive integers" especially since
all the answers are products of 2 positive integers.
[quote="ash_maverick"]x and y are positive integers. , what is the value of xy?
(A) 48
(B) 36
(C) 24
(D) 18
(E) 12--ans
Please explain[/quote]
I'm guessing the word missing here is "consecutive" positive integers,
in which case only 3*4 = 12 would make the cut. Else, it would be impossible to find out xy from just "positive integers" especially since
all the answers are products of 2 positive integers.
[quote="ash_maverick"]x and y are positive integers. , what is the value of xy?
(A) 48
(B) 36
(C) 24
(D) 18
(E) 12--ans
Please explain[/quote]