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#1 2011-12-15 08:56:19
- jeff111
- Guest
three unknowns
hi I'm having trouble with this equation any help would be great. 3g - 2h=-2
g + f = 2.4
f4 - h = 7.3
Thankyou if anyone can help!
#2 2011-12-15 09:25:17
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: three unknowns
Hi jeff111;
What is f4? You have 4 unknowns.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#3 2011-12-15 09:47:06
- jeff111
- Guest
Re: three unknowns
4f sorry
#4 2011-12-15 09:57:22
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: three unknowns
That is okay.
If you would enter them as fractions and whole numbers you get a somewhat cleaner answer.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#5 2011-12-15 10:24:13
- jeff111
- Guest
Re: three unknowns
thanks any chance of workings so i can understand how to do it I've worked through some two unknown equations thanks
#6 2011-12-15 10:34:48
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: three unknowns
Hi;
There are lots of ways to solve these but two that are standard are substitution or elimination.
If we multiply the 2 nd equation by 4 we get.
Now we can subtract the 3rd equation from the 2nd. We get:
Now you have a 2 x 2 system of equations that are:
Can you handle it from here?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
#7 2011-12-15 10:47:58
- jeff111
- Guest
Re: three unknowns
yes thank you
#8 2011-12-15 11:03:16
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: three unknowns
Very good! You are welcome and welcome to the forum.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
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