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exponent and root

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exponent and root

by deepoe » Mon Mar 09, 2009 4:58 am
If x =4 , then -2^2 radical X + 2 =

A. - 14
B. -8
C. -2
D. 0
E. 18


I had chosen E, but it is A :S

-2^2 x 2 = -2^4 +2 = -2 x -2 x -2 x -2 + 2 = 16 + 2 = 18 ?

How can -2^4 be -14 ?
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by DanaJ » Mon Mar 09, 2009 5:04 am
-2^[2 + sqrt(4)] = -2^4 = -16.
Now, you're looking for -16 + 2 = -14.
The thing that might have confused you is that the minus sign:
a. since the minus sign is in fron of 2, then you get that -2^4 = -(2^4) = -16
b. had the minus sign been placed like so: (-2)^4 - then indeed you get that (-2)^4 = 16.
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by devesh99 » Mon Mar 09, 2009 5:06 pm
What is radical in this question??? can some one explain
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by devesh99 » Mon Mar 09, 2009 5:07 pm
What is radical in this question??? can some one explain
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by DanaJ » Tue Mar 10, 2009 4:34 am
I attached a photo. Hope it clears things out...
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