SOLUTION: Hi, my name is Brandon Jones. I'm in the 12th grade and I'm taking AP Calculus. School just started for me on Thursday, 08/04/11 and I am a little rusty. I am having trouble with s

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Question 478578: Hi, my name is Brandon Jones. I'm in the 12th grade and I'm taking AP Calculus. School just started for me on Thursday, 08/04/11 and I am a little rusty. I am having trouble with solving for indicated variables. Here's one of the problems and what I have so far:
V=2(ab+bc+ac); a (looking for a)....this is what I got so far:V=2ab+2bc+2ac, then I did: V-2bc=2ab+2ac.....I'm stuck.
It would be great if I can see the steps and understand what I'm doing. Thanks!
Found 2 solutions by ankor@dixie-net.com, Theo:
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
V - 2bc = 2ab + 2ac
At this point factor out a
V - 2bc = a(2b + 2c)
Divide both sides by (2b + 2c)
a = or

Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
V = 2*(ab + bc + ac)
reorder the terms to get:
V = 2*(ab + ac + bc)
factor out the a to get:
V = 2*(a(b+c) + bc)
expand the equation to get:
V = 2a(b+c)+2bc
subtract 2bc from both sides of the equation to get:
V-2bc = 2a(b+c)
divide both sides by (b+c) to get:
(V-2bc)/(b+x) = 2a
divide both sides by 2 to get:
(V-2bc)/(2(b+c)) = a
commute to get:
a = (V-2bc)/(2(b+c))
assuming a = 1, b = 2, c = 3, your original equation gets:
V = 2*(2+6+3) = 2*11 = 22
plug the values for V and b and c into the final equation to get:
(22-12)/(2(5)) = a which becomes:
10/10 = 1 which is the value of a we started out with, so the conversion formula looks good.
i think that's your answer.
check it out for yourself to see if it works for you.