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September 6th, 2012, 12:51 PM   #1
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Alg help, multi variable

I got a couple multi variable equations I'm stuck on, I can't figure out what I'm doing wrong. One of them that's not multi variable is 19t- (2(t-1)/19) = 20 solve for T, I got 382/359 but it comes out to equal 20.2 something. Another one is u(v-+w(v-4)=z(v-1), help please.
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September 6th, 2012, 12:56 PM   #2
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Re: Alg help, multi variable

For the second equation, assuming u, w, and z are constants, then we simply solve for v:











There are infinitely many solutions in all four variables: just pick values for u, w, and z such that and then calculate the value for v using the above equation.
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September 6th, 2012, 12:59 PM   #3
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Re: Alg help, multi variable

Show your work for the first problem.
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September 6th, 2012, 01:03 PM   #4
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Re: Alg help, multi variable

For the first problem:



Multiply through by 19:









For the second problem, there will not necessarily be a unique solution, you may solve for one variable in terms of the other three.
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September 6th, 2012, 01:15 PM   #5
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Re: Alg help, multi variable

Quote:
Originally Posted by MarkFL
For the first problem:



Multiply through by 19:









For the second problem, there will not necessarily be a unique solution, you may solve for one variable in terms of the other three.
How did you get 20.2?
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September 6th, 2012, 01:57 PM   #6
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Re: Alg help, multi variable

I typed the wrong problem, it was v+8, but I redid the problem exactly as you showed and my online homework thing said it was wrong. I double checked it and everything, I'll have to ask the teacher tomorrow. I got one more problem that I want to make sure I got right,

At-b/c-b(1-5t) = 9

at-b/c-b+5bt=9

At-B= 9(c-b+5tb)

At-B=9c-9b+45Bt

At-45Bt=9c-8B

t(A-45B)=9c-8B

t=9C-8B/A-45B

Is that correct?
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September 7th, 2012, 12:42 PM   #7
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Re: Alg help, multi variable

Be careful with using paraentheses. For example the last line should read t=(9C-8B)/(A-45B). Without the parentheses it looks wrong.

Going from the first to the second line looks like also missing parentheses.
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