You are Here: Home >< Maths

Is (m-n) equivalent to (n-m)? watch

1. So this is a halfway solution by TeeEm on arthimetic sequence [Question 124]
And I was wondering if (m-n) equivalent to (n-m)?

I've also noticed that 2 was changed to -2 so aren't you supposed to change (m+n) to (-n-m) ??

Attached Images

So this is a halfway solution by TeeEm on arthimetic sequence [Question 124]
And I was wondering if (m-n) equivalent to (n-m)?

I've also noticed that 2 was changed to -2 so aren't you supposed to change (m+n) to (-n-m) ??

It goes from 2(m-n)(m+n) to -2(m+n)(n-m). Notice the minus sign in the front.
So this is a halfway solution by TeeEm on arthimetic sequence [Question 124]
And I was wondering if (m-n) equivalent to (n-m)?

I've also noticed that 2 was changed to -2 so aren't you supposed to change (m+n) to (-n-m) ??

Yes, that's right because he essentially took a factor of -1 out of (m-n) and put it on the outside of the bracket. All of the terms are being multiplied together so the expressions are equivalent, but written differently.
4. (m-n) = -(n-m)

if m+n was changed to -n-m then it would cancel out with the -2
5. (Original post by rayquaza17)
It goes from 2(m-n)(m+n) to -2(m+n)(n-m). Notice the minus sign in the front.
(Original post by pineneedles)
Yes, that's right because he essentially took a factor of -1 out of (m-n) and put it on the outside of the bracket. All of the terms are being multiplied together so the expressions are equivalent, but written differently.
Oh I see !! Thank you!!
6. (Original post by qsom)
(m-n) = -(n-m)

if m+n was changed to -n-m then it would cancel out with the -2
Great!! Thank you!!

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: May 23, 2016
Today on TSR

Cambridge interviews

Find out who is getting invitations

University open days

• Heriot-Watt University
School of Textiles and Design Undergraduate
Fri, 16 Nov '18
• University of Roehampton
Sat, 17 Nov '18
• Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 17 Nov '18
Poll
Useful resources

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams

Chat with other maths applicants