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

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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

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