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basic maths :S

NeedhelponthisquestionplsNeed help on this question pls

x(2x−1/4)4x(2x^{-1/4})^4

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Original post by Skaterkid
NeedhelponthisquestionplsNeed help on this question pls

x(2x−1/4)4x(2x^{-1/4})^4


Here's the first step:
x×24x−1/44x\times2^4x^{-1/4^{4}}
Reply 2
Avatar for Skaterkid
Skaterkid
OP
9
Original post by Bakes0011
Here's the first step:
x×24x−1/44x\times2^4x^{-1/4^{4}}


16x−1/416x^{-1/4} X x1 x^1
Reply 3
Avatar for Hasufel
Hasufel
16
x(2x^-1/4))^4=x(2^4)(1/x^(1/4 x4))
=x(16)(1/x)

look again, Skaterkid - i should have put x^-1/4, as it now is above.

if you do the bracket first, what`s inside it is: 16/(x^1/4)^4 because the exponent of x is negative, and: 1/a=a^-1, so, 1/a^(1/4)=a^(-1/4)
(edited 12 years ago)
Reply 4
Avatar for Skaterkid
Skaterkid
OP
9
still dont understand how the answer is 16 or 2 to the power 4
Reply 5
Avatar for lubus
lubus
12
Original post by Skaterkid
NeedhelponthisquestionplsNeed help on this question pls

x(2x−1/4)4x(2x^{-1/4})^4


x(16x^-1)

16x / x = 16.
okay forgot the x in the question for now, put it in later.
when you're doing (2x−1/4)4(2x^{-1/4})^4 its basically like doing (24(x−1/4)4)(2^4 (x^{-1/4})^4) and multiply that by x.
Original post by Skaterkid
16x−1/416x^{-1/4} X x1 x^1


No, you got the 16x16x bit right, but it's x−1/44x^{-1/4^{4}}, which is the same as x4×−1/4x^{4\times -1/4}.

{mod: full solution removed}
(edited 12 years ago)
Reply 8
Avatar for MissBrown
MissBrown
1
What was the original question??????
You call that basic!? :eek:
Reply 10
Avatar for Mr Young
Mr Young
8
Original post by YorkieLad101
You call that basic!? :eek:


exactly what I was thinking hahaha! I can't deal with maths.... :///
Reply 11
Avatar for TheJ0ker
TheJ0ker
11
Original post by Skaterkid
NeedhelponthisquestionplsNeed help on this question pls

x(2x−1/4)4x(2x^{-1/4})^4


Is that from an edexcel C1 past paper? Because I'm pretty sure that was the first question of my C1 exam.
Reply 12
Avatar for MissBrown
MissBrown
1
Original post by YorkieLad101
You call that basic!? :eek:


Assuming the question is asking you to simplify the expression, it can be done with two pieces of info you learn at GCSE level about the rules of indices and essentially 2-3 'moves' raising to powers.
Original post by MissBrown
Assuming the question is asking you to simplify the expression, it can be done with two pieces of info you learn at GCSE level about the rules of indices and essentially 2-3 'moves' raising to powers.


errr excuse me? that makes no sense!
Reply 14
Avatar for MissBrown
MissBrown
1
Original post by YorkieLad101
errr excuse me? that makes no sense!


It makes no sense to you for one of the following reasons:

(i) You have not yet been exposed to higher mathematics at GCSE
(ii) You didnt understand or learn it when taught

Either way, Im not quite sure why you would post in a mathematics forum that goes through to University level with a comment such as "you call that basic"
For many it will be very basic which I feel you may need to appreciate when posting in such fora.
Original post by YorkieLad101

Original post by YorkieLad101
errr excuse me? that makes no sense!


Read up on how to work with indices (Any GCSE text will do - it starts toward the top range of Foundation, but some is also in Higher Tier as well) It is quite simple once you have done it a couple of times
Original post by MissBrown
Either way, Im not quite sure why you would post in a mathematics forum that goes through to University level with a comment such as "you call that basic"
For many it will be very basic which I feel you may need to appreciate when posting in such fora.


because i can! :biggrin:
Original post by lubus
x(16x^-1)

16x / x = 16.


This. Please explain it though how you got to this so OP understands
Reply 18
Avatar for MissBrown
MissBrown
1
Original post by YorkieLad101
because i can! :biggrin:


I think I shall leave it there :smile:
Original post by MissBrown
I think I shall leave it there :smile:


cheers for that!

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