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# I thought this was an easy problem

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Senior Manager
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I thought this was an easy problem [#permalink]  30 Oct 2006, 18:16
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
I thought this was an easy problem
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Senior Manager
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yes it is ...... A is the answer...

2^9/2= 2^8
Senior Manager
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gmacvik wrote:
yes it is ...... A is the answer...

2^9/2= 2^8

d'oh!! I multiplied 3*2 instead of 3^2

thx!
Senior Manager
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I did the same thing becuase I thought you use the "power rule here"

Power Rule

The "power rule" tells us that to raise a power to a power, just multiply the exponents. Here you see that 5^2 raised to the 3rd power is equal to 5^6.

x^mn = x^mn
(5^2)^3 = 5^6

Can some please clarify? When do use this rule instead of what was done in the original posting? Thanks so much
_________________

"Never let the fear of striking out get in your wayâ€

Director
Joined: 01 Oct 2006
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Matrix02 wrote:
I did the same thing becuase I thought you use the "power rule here"

Power Rule

The "power rule" tells us that to raise a power to a power, just multiply the exponents. Here you see that 5^2 raised to the 3rd power is equal to 5^6.

x^mn = x^mn
(5^2)^3 = 5^6

Can some please clarify? When do use this rule instead of what was done in the original posting? Thanks so much

I too applied the same logic earlier was shocked to see the answer.
But then realised that there is bracket missing
if 2^(4-1)^2 it actually of the form x^y whereas if it was ((2^(4-1))^3) then we could use the power rule.
Hope this helps
Yogesh
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yogeshsheth wrote:
Matrix02 wrote:
I did the same thing becuase I thought you use the "power rule here"

Power Rule

The "power rule" tells us that to raise a power to a power, just multiply the exponents. Here you see that 5^2 raised to the 3rd power is equal to 5^6.

x^mn = x^mn
(5^2)^3 = 5^6

Can some please clarify? When do use this rule instead of what was done in the original posting? Thanks so much

I too applied the same logic earlier was shocked to see the answer.
But then realised that there is bracket missing
if 2^(4-1)^2 it actually of the form x^y whereas if it was ((2^(4-1))^3) then we could use the power rule.
Hope this helps
Yogesh

Yogesh, so what you're saying is this? That's sneaky!!!
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Senior Manager
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Doe anyone have a website or rule for this case? I need to review this one in more detail for sure so I don't get fooled again. I am not to clear on the parenthesis and that works...
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"Never let the fear of striking out get in your wayâ€

Director
Joined: 01 Oct 2006
Posts: 500
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Kudos [?]: 18 [0], given: 0

Nsentra wrote:
yogeshsheth wrote:
Matrix02 wrote:
I did the same thing becuase I thought you use the "power rule here"

Power Rule

The "power rule" tells us that to raise a power to a power, just multiply the exponents. Here you see that 5^2 raised to the 3rd power is equal to 5^6.

x^mn = x^mn
(5^2)^3 = 5^6

Can some please clarify? When do use this rule instead of what was done in the original posting? Thanks so much

I too applied the same logic earlier was shocked to see the answer.
But then realised that there is bracket missing
if 2^(4-1)^2 it actually of the form x^y whereas if it was ((2^(4-1))^3) then we could use the power rule.
Hope this helps
Yogesh

Yogesh, so what you're saying is this? That's sneaky!!!

Nsentra
A normal exponent rule is (x^m)^n =x^(m*n) which holds true if you have if you x^m and the whole raise to n.
Thus x^(4-1)^2 !=((x^(4-1))^2).
Because if you follow PEDMAS x^(4-1)^2 =x^(3)^2=x^9
Correct me If I am wrong.
Senior Manager
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OK lets go step by step

Numerator---

consider the powers of 2
4-1=3
square of 3 ===> 9

So numerator becomes 2^9

Denominator
3-2=1
hence 2^1

so the equation becomes

2^9 / 2^1

==> 2^8.

Hope I am clear now and it helps you
Senior Manager
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anindyat wrote:
2^8

Ok.

so do you guys concur that had the problem said [2^(4-1)]^2 then the answer would be 2^5?

Just trying to finalize the whole power rule.
Senior Manager
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Nsentra wrote:
anindyat wrote:
2^8

Ok.

so do you guys concur that had the problem said [2^(4-1)]^2 then the answer would be 2^5?

Just trying to finalize the whole power rule.

I think I am slowly (and I do mean slowly) getting this. The palcement of the paren

Nsentra - I think you meant to say [2^(4-1)]^2/2^3-2

This would equal 2^5

(2^(4-1))^2/2^3-2 = 2^5

Would (2^4-1)^2/2^3-2 also = 2^5???
_________________

"Never let the fear of striking out get in your wayâ€

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