Exponent Question from MBa.com

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Exponent Question from MBa.com

by mlk82 » Wed Dec 03, 2008 7:01 pm
Hello all,

Question for you all that comes directly from a Practice Test from MBa.com

Base 2 to the exponent(4-1) to exponent 2
/
Base 2 to the exponent 3-2


Since we have a common base (2) , this questions seems pretty straight forward. We simply have to follow the exponent and pedmas rules to find that exponent (4-1) = 3 x exponent 2 = base 2 to the exponent 6

/


base 2 to the exponent 3-2 which gives us 2 to exponent 1

We are then left with 2 exponent 6
/
2 exponent 1

which gives un 2 exponent 5.



THe official answer is 2 exponent 8 ...... I can see how you get there if you square the first exponent (4-1) , which would be 2 exponent 9/ 2 exponent 1 = 2 exponent 8

but since when do you not multiply an exponent in a bracket by an exponent to that bracket?????

ANy help would be appreciated
Source: — Problem Solving |

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by Zipper » Thu Dec 04, 2008 3:53 am
Your math is wrong.

2^((4-1)^2)=2^((4^2)-2.4.1+(1^2))=2^9 so it is 2^9/2^1=2^9/2=2^8

for better understanding:

(a-b)^2=a^2-2ab+b^2
(4-1)^2=(4^2)-2.4.1+1^2=9. I don't know why you felt you have to do it like this: (4-1)^2=3*2=6 in my understanding.

Hope this helps.

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I got the same problem, and made the same mistake.

(x^a)^b = x^ab is different from x^(a^b)


In the absence of brackets, I think the only way to figure out what's being asked is to look at the font sizes. Exponents usually have a smaller font than the base, and an exponent of the exponent will have a still smaller size.

Not scientific, but kinda makes sense.