Solve: C = A - B/AB, f or B

[vannahbabyx3]

We were given the problem below for biochemistry summer homework. I am going to be taking calculus this year, but I can't remember how to do this problem to save my life. There are possible answers, which I will also post below, but I just don't want to pick one and get it wrong. Help?

Solve: C = A - B/AB, f or B

a) B = CA +1
b) B = CA +1/A
c) B = 1/C +A
d) B = A/(CA +1)

Thanks! =)

 

[Loren]

<Solve: C = A - B/AB, for B

As written this means \(\displaystyle C=A-\frac{B}{AB}\)

Obviously you cannot solve that for B because B/B = 1 leaving you with C=A-1/A.
First order of business is to use parenthesis to let us know what the original statement truly is.

 

[vannahbabyx3]

I'm sorry if I wasn't clear on the original equation.

Solve: C = (A-B)/AB, f or B.

I thought that B would end up canceling out when I first took a look at it, so that is why I am still unsure on how to solve this problem.

 

[Loren]

< C = (A-B)/AB, for B.

Multiply both sides by AB.
Add B to both sides.
On the left side factor out B.
Divide both sides by AC+1.

 

[stapel]

Solve: C = (A-B)/AB, f or B.

What is the meaning of "f or B"? There is no "f" in the exercise, as currently posted.... Or is that supposed to be a continuation of the directions...? "Solve: for B"...?

Assuming the latter:

I thought that B would end up canceling out...

Since only factors cancel, and since the numerator contains no factor of "B", with what would the denominator's factor "cancel out"...? Also, since you say you got as far as "ending up" where you thought B would cancel out, so then you must have done some work on this exercise. In future, it might be helpful if you showed your work, so we can "see" what you are doing and where you may be going wrong.

Following the customary route, try multiplying both sides by the denominator, thus getting rid of the fraction. Collect the terms containing B on one side of the "equals" sign, with any other terms on the other side. Factor the B out front, and divide off whatever is left.

If you get stuck, please reply with a clear listing of your work and reasoning so far. Thank you!

Eliz.