You are Here: Home >< Maths

# Could you show me a simple way to work these equations out? Watch

1. I know this is probably very easy, but I just can't get my head round it, how would you go about working out the following equations?

2k/5 - k/2 = 1

a/3 + a/5 = 1

x/2 + x/3 + x/4 = 1

Many thanks
2. (Original post by theoallen)
I know this is probably very easy, but I just can't get my head round it, how would you go about working out the following equations?

2k/5 - k/2 = 1

a/3 + a/5 = 1

x/2 + x/3 + x/4 = 1

Many thanks
.

i,e: 2/5 lots of k minus half a lot of k gives -1/10 lots of k.

So now you want to find a number such that if you multiply it by -1 and divide it by 10 you get 1.

This number is trivially .

Can you go through a similar procedure for the other questions now?

What is a/3 + a/5? i.e: 1/3 lots of a added to 1/5 lots of a?
3. (Original post by Zacken)
.

i,e: 2/5 lots of k minus half a lot of k gives -1/10 lots of k.

So now you want to find a number such that if you multiply it by -1 and divide it by 10 you get 1.

This number is trivially .

Can you go through a similar procedure for the other questions now?

What is a/3 + a/5? i.e: 1/3 lots of a added to 1/5 lots of a?
Okay so I did that and got an answer of 9, but e book says the answer is 6, what did I do wrong?
4. (Original post by theoallen)
Okay so I did that and got an answer of 9, but e book says the answer is 6, what did I do wrong?
Can't tell what question you're talking about.

Can't read minds and don't know what you've done. So you'll need to show me what you've done before I can point out where you've gone wrong.
5. (Original post by Zacken)
Can't tell what question you're talking about.

Can't read minds and don't know what you've done. So you'll need to show me what you've done before I can point out where you've gone wrong.
The 2k/3 - k/2 = 1 question. I keep running around in circles. I don't understand how you got k\left(\frac{2}{5} - \frac{1}{2}\right) = 1 \iff -\frac{k}{10} = 1 where did the 1/2 come from? And how did you get the -k/10?

And then when I put the right answer 6 in, I multiply it by -1 and divide it by 10 but get 0.5?

I'm literally so so confused

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 22, 2016
Today on TSR

### How to stand out in an Oxbridge interview

What makes you memorable?

### A pregnant woman visits me every night

Discussions on TSR

• Latest
• ## 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.

• 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

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## 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.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE