Fayeeeee
Badges: 13
Rep:
?
#1
Report Thread starter 1 year ago
#1
I’m not sure how to do 2 Attachment 802982Attachment 802984
0
reply
RDKGames
Badges: 20
Rep:
?
#2
Report 1 year ago
#2
(Original post by Fayeeeee)
I’m not sure how to do 2
An odd number represented algebraically is 2n+1, so what is (2n+1)^3 ?
0
reply
Fayeeeee
Badges: 13
Rep:
?
#3
Report Thread starter 1 year ago
#3
(Original post by RDKGames)
An odd number represented algebraically is 2n+1, so what is (2n+1)^3 ?
Name:  8829A401-B0FF-4130-820A-A7A9C2E1FA43.jpg.jpeg
Views: 11
Size:  38.7 KB is that right
0
reply
Fayeeeee
Badges: 13
Rep:
?
#4
Report Thread starter 1 year ago
#4
(Original post by RDKGames)
An odd number represented algebraically is 2n+1, so what is (2n+1)^3 ?
Also I don’t really understand 5 Name:  409B64AB-B6F6-459E-BFEB-3D911F9234E5.jpg.jpeg
Views: 11
Size:  31.2 KB
0
reply
RDKGames
Badges: 20
Rep:
?
#5
Report 1 year ago
#5
(Original post by Fayeeeee)
is that right
Yeah that's right. To show that it's an odd number, you should explicitly try and get it into the form:

2 \times \text{(something)} + 1.
0
reply
RDKGames
Badges: 20
Rep:
?
#6
Report 1 year ago
#6
(Original post by Fayeeeee)
Also I don’t really understand 5
Look at the LHS. Is it an even or an odd number??

Then that must be the case for the RHS, and since 5 is an odd number, it leaves only one option as to whether x is even or odd.
0
reply
Fayeeeee
Badges: 13
Rep:
?
#7
Report Thread starter 1 year ago
#7
(Original post by RDKGames)
Yeah that's right. To show that it's an odd number, you should explicitly try and get it into the form:

2 \times \text{(something)} + 1.
Ahh okay thanks
0
reply
Fayeeeee
Badges: 13
Rep:
?
#8
Report Thread starter 1 year ago
#8
(Original post by RDKGames)
Look at the LHS. Is it an even or an odd number??

Then that must be the case for the RHS, and since 5 is an odd number, it leaves only one option as to whether x is even or odd.
I know x is an odd number but I don’t understand how to get it into that from
0
reply
RDKGames
Badges: 20
Rep:
?
#9
Report 1 year ago
#9
(Original post by Fayeeeee)
I know x is an odd number but I don’t understand how to get it into that from
You don't need to get x into the form 2n+1, if that's what you're asking.

In this question you don't use algebra to answer it so no need to introduce that form.
0
reply
Fayeeeee
Badges: 13
Rep:
?
#10
Report Thread starter 1 year ago
#10
(Original post by RDKGames)
You don't need to get x into the form 2n+1, if that's what you're asking.

In this question you don't use algebra to answer it so no need to introduce that form.
I don’t know what to do, do I rearrange idk
0
reply
RDKGames
Badges: 20
Rep:
?
#11
Report 1 year ago
#11
(Original post by Fayeeeee)
I don’t know what to do, do I rearrange idk
You just said you know that x is odd. [which I'm interpreting as you telling me you have logically deduced this is true]

You have answered the question and don't need to do anything further!
0
reply
Fayeeeee
Badges: 13
Rep:
?
#12
Report Thread starter 1 year ago
#12
(Original post by RDKGames)
You just said you know that x is odd. [which I'm interpreting as you telling me you have logically deduced this is true]

You have answered the question and don't need to do anything further!
I need to put it into this form Name:  F055199B-C78D-4727-8F11-4C4D262F6B3C.jpg.jpeg
Views: 7
Size:  18.9 KB
0
reply
RDKGames
Badges: 20
Rep:
?
#13
Report 1 year ago
#13
(Original post by Fayeeeee)
I need to put it into this form
Ok, well they took the algebraic approach.

Do you understand how to start at 2(x-n) = x+5 and rearrange for x, first of all?
0
reply
Fayeeeee
Badges: 13
Rep:
?
#14
Report Thread starter 1 year ago
#14
(Original post by RDKGames)
Ok, well they took the algebraic approach.

Do you understand how to start at 2(x-n) = x+5 and rearrange for x, first of all?
No😂
0
reply
RDKGames
Badges: 20
Rep:
?
#15
Report 1 year ago
#15
(Original post by Fayeeeee)
No😂
Expand the LHS first.

Then have a go.
0
reply
Fayeeeee
Badges: 13
Rep:
?
#16
Report Thread starter 1 year ago
#16
(Original post by RDKGames)
Expand the LHS first.

Then have a go.
Name:  BFC7CC43-7298-402B-8023-2E3AE4B522AB.jpg.jpeg
Views: 10
Size:  28.2 KB
0
reply
RDKGames
Badges: 20
Rep:
?
#17
Report 1 year ago
#17
(Original post by Fayeeeee)
...
Come on...

Subtract x from both sides...
0
reply
Fayeeeee
Badges: 13
Rep:
?
#18
Report Thread starter 1 year ago
#18
(Original post by RDKGames)
Come on...

Subtract x from both sides...
i don’t understand why in the mark scheme the brackets has n+2 as u thought odd numbers could only be n+1,n+3 for example
0
reply
Fayeeeee
Badges: 13
Rep:
?
#19
Report Thread starter 1 year ago
#19
(Original post by Fayeeeee)
i don’t understand why in the mark scheme the brackets has n+2 as u thought odd numbers could only be n+1,n+3 for example
I meant as I
0
reply
RDKGames
Badges: 20
Rep:
?
#20
Report 1 year ago
#20
(Original post by Fayeeeee)
i don’t understand why in the mark scheme the brackets has n+2 as u thought odd numbers could only be n+1,n+3 for example
No, odd numbers (as I've mentioned previously!) are of the form 2 \times \text{(something)} + 1 so in this question, the 'something' is precisely n+2.

This 'something' can be whatever as long as it's an integer, and n+2 is definitely an integer. So that's no issue!
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (147)
14.54%
I'm not sure (43)
4.25%
No, I'm going to stick it out for now (303)
29.97%
I have already dropped out (26)
2.57%
I'm not a current university student (492)
48.66%

Watched Threads

View All