## Literal equations that can't be solved?

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.
dipetersen
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### Literal equations that can't be solved?

I have a literal equation that I am supposed to solve for 'a' but I think it is an equation that can't be rewritten. Can someone confirm this for me?

x=(a+b+c)/ab solve for a

I say it can't be solved. Am I wrong?
Thanks

stapel_eliz
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x=(a+b+c)/ab solve for a

I say it can't be solved. Am I wrong?
Sorry, but yes. This can be solved; it just requires a "trick". You can learn about that trick in this lesson. (Scroll down about two-thirds of the way, to the example showing "Solve Q = 3a + 5ac for a". You'll need to cross-multiply in your equation first, to get rid of the denominator.)

dipetersen
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### Re: Literal equations that can't be solved?

I looked at that and maybe I'm missing a step.

By cross-multiply, I assume that you mean

x= (a+b+c)/ab
xab = a+b+c

Then if I subtract b & c from both sides I get

xab - b - c = a

My problem is that I do not know how to get the a out of the xab.

stapel_eliz
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xab - b - c = a

My problem is that I do not know how to get the a out of the xab.
Now do like the example showed: Get the terms containing the target variable together on one side, factor, and divide.

dipetersen
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### Re: Literal equations that can't be solved?

So if I understand that correctly, it would look something like:

-(b+c)/(1-xb) = a

Right? Thanks for the hints,BTW.

stapel_eliz
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So if I understand that correctly, it would look something like:

-(b+c)/(1-xb) = a
Yep!

dipetersen
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Joined: Wed Oct 05, 2011 1:43 am
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### Re: Literal equations that can't be solved?

Awesome! Thanks for the help.