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simultaneous equation with fraction

Hi all
I have been trying to work this equation out for 4 hours now. I just don't know where to start. Please, could you help me.

2/x+y=4/25

1/2x-y=4/32
Original post by LaReina
Hi all
I have been trying to work this equation out for 4 hours now. I just don't know where to start. Please, could you help me.

2/x+y=4/25

1/2x-y=4/32


Is that 2x+y=425 or 2x+y=425\frac{2}{x}+y=\frac{4}{25} \mathrm{\ or\ }\frac{2}{x+y}=\frac{4}{25} ?
Reply 2
Avatar for LaReina
LaReina
OP
7
Original post by brianeverit
Is that 2x+y=425 or 2x+y=425\frac{2}{x}+y=\frac{4}{25} \mathrm{\ or\ }\frac{2}{x+y}=\frac{4}{25} ?


it is the latter.
Original post by LaReina
Hi all
I have been trying to work this equation out for 4 hours now. I just don't know where to start. Please, could you help me.

2/x+y=4/25

1/2x-y=4/32


Is that 2x+y=425 or 2x+y=425\frac{2}{x}+y=\frac{4}{25} \mathrm{\ or\ }\frac{2}{x+y}=\frac{4}{25} ?
Whichever it is, clear your fractions by multiplying through by a common denominator which should leave you with a pair of simple simultaneous equations.
Original post by LaReina
Hi all
I have been trying to work this equation out for 4 hours now. I just don't know where to start. Please, could you help me.

2/x+y=4/25

1/2x-y=4/32

Find a common denominator and multiply both sides by it :biggrin:
Reply 5
Avatar for TutorTrish
TutorTrish
It's the denominators that are making life tricky for you, so the first thing you need to do is multiply both sides of the equation by that denominator so you have now eliminated that problem...
so your 2/(x+y) =4/25 becomes 2 x 25 = 4(x+y)
This looks far more friendly and more of the type of equation you deal with in simultaneous equations.
You need to do the same with the other one too....

Good luck!
Reply 6
Avatar for LaReina
LaReina
OP
7
Original post by brianeverit
Is that 2x+y=425 or 2x+y=425\frac{2}{x}+y=\frac{4}{25} \mathrm{\ or\ }\frac{2}{x+y}=\frac{4}{25} ?
Whichever it is, clear your fractions by multiplying through by a common denominator which should leave you with a pair of simple simultaneous equations.


I have tried doing that and I have ended up with x+y on both sides. This is very confusing, :confused:
Reply 7
Avatar for iamtheyoyo
iamtheyoyo
Is this in A level maths? What module, and what exam board?
Original post by LaReina
I have tried doing that and I have ended up with x+y on both sides. This is very confusing, :confused:

Then just rearrange and substitute in when you're done.
Reply 9
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thisworked
Try cross-multiplying which will result in 2*25 = 4(x+y)
Reply 10
Avatar for TutorTrish
TutorTrish
Original post by LaReina
I have tried doing that and I have ended up with x+y on both sides. This is very confusing, :confused:


You will end up with 2 equations that have both x and y in them...a pair of linear simultanous equations.

If you have multiplied up to get rid of your denominators...one equation is
2 x 25 = 4(x + y) and the other is 1 x 32 = 4(2x - y) ( If I have interpreted your original equations correctly)...

The solutions are fractions.
Original post by LaReina
I have tried doing that and I have ended up with x+y on both sides. This is very confusing, :confused:


Then collect the x's and y's together on one side. Then after simplifying you should have x+y=25 and 2x-y=8
(edited 10 years ago)
Reply 12
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LaReina
OP
7
Thank you everyone for your help. I manage to get the answer in the end! :biggrin:
Reply 13
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TutorTrish
Brilliant! I think you were just getting bogged down by it.
Reply 14
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TutorTrish
Original post by LaReina
Thank you everyone for your help. I manage to get the answer in the end! :biggrin:


Brilliant! I'm glad you got there in the end.

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