Question

Help!
Solve the following formula for the specified variable :
L=a+(b-1)w for b

Answer 1

hi. you can start this problem by subtraction of a from both sides.

Answer 2

I tried that but then I got stuck.

Answer 3

ok. what was the result of that step? something like L-a=(b-1)w?

Answer 4

yes that's what I got.

Answer 5

and then do I divide both sides by w? I'm not sure

Answer 6

perfect. you are on the right track.

Answer 7

yes. divide both sides by w. what do you get?

Answer 8

So I got L-a/w = (b-1). So do I add 1 now?

Answer 9

It doesn't look right.

Answer 10

just to be clear, it should be (L-a)/w=b-1. the parentheses indicate that w divides L-a and just a. ok? It is a matter of good form.

Answer 11

then you add 1....and voila! you have done the problem.

Answer 12

so what do you get for the final answer?

Answer 13

So I got L-a/w +1 as the final answer. Is that right?

Answer 14

did you see what i wrote above about the parentheses? The answer is (L-a)/w+1=b. Overall, nice work PhiBee, or is it Jay. lol

Answer 15

Thank you! And it's PhiBee :)

Answer 16

well, it is a pleasure PhiBee. You did well. :) Is there anything else with which I can be of service?

Answer 17

Well I do have one more similar question?

Answer 18

fire away

Answer 19

The question asked to solve for b1 in the equation N=b1-b2/g

Answer 20

ok. I know that books can make a straight fraction line. Does the fraction line extend beneath both b1 and b2. \[\frac{ b1-b2 }{ g }\]...like this?

Answer 21

yes :)

Answer 22

so what do you think your first step might be?

Answer 23

Can I multiply by g to get rid of it?

Answer 24

absolutely. if you multiply by g you are no longer dealing with a fraction. makes it sooo much easier.

Answer 25

So I have to multiply g on both sides?

Answer 26

yes... the rules of algebra state that what you do to one side in solving an equation, you must do to the other side as well. so what was the result of that operation?

Answer 27

I got N x g = b1- b2

Answer 28

perfect! you have this thing in hand. Now, the last step is....?

Answer 29

I add b2?

Answer 30

right again... and your answer is...?

Answer 31

Ng+b2 = b1 ?

Answer 32

you got it... nicely done PhiBee :)

Answer 33

Yay! Thank you!

Answer 34

you are welcome. any other problems giving you a little doubt?

Answer 35

There are two more I might need help with if that's ok?

Answer 36

:) sure. fire away

Answer 37

Ok. The first question asks to solve the following formula for the specified variable: A=1/2 pi n^2 f for f. Sorry i don't have the pi sign.

Answer 38

so what do you think your first move is here?

Answer 39

Can I multiply by 2?

Answer 40

yes... now let me be clear. the problem is 1/2 times pi times n^2 times f. None of the variables appear in a denominator. right?

Answer 41

yes

Answer 42

then multiply away (by 2 of course). :))

Answer 43

So I get 2A = pi n^2 f ?

Answer 44

right PhiBee. now the rest is a product of pi and n^2 and f. you can get to the answer in two steps or one.

Answer 45

do you see what I mean?

Answer 46

So can i divide by pi?

Answer 47

yes. that'll get you there in two steps.

Answer 48

So I would get 2A/pi = n^2 f ?

Answer 49

looking good so far...

Answer 50

and the last step (the envelope please, if you watch the academy awards) is....

Answer 51

Ok I'm stuck because I want to get rid of n^2. How do I do that?

Answer 52

how would you get rid of it if it was just n?

Answer 53

I can't square root it can I ?

Answer 54

no, you dont need to square root here.

Answer 55

how would you solve this if it werent n^2, just n?

Answer 56

I would divide both sides by n.

Answer 57

right. so now how would you isolate f from n^2?

Answer 58

give me a guess. your best guess

Answer 59

I divide by f?

Answer 60

no wait that was wrong....

Answer 61

PhiBee, you are solving for f.

Answer 62

:) good that you caught that

Answer 63

you know that you can divide by any power of a variable, safely and securely. lol

Answer 64

This power is really aggravating me. How do I get rid of it?!

Answer 65

you dont get rid of the power. it is ok to divide by n^2.

Answer 66

look at what i wrote above. you can divide by any power of a variable.

Answer 67

Oh wait it's ok? That was my first guess the whole time!!! i just thought it wasn't possible!

Answer 68

you are solving for f, not for n. no square root need be taken. Remember which variable you are solving for. :) now what did you get for an answer?

Answer 69

So then i would FINALLY get 2A/ pi n^2. PLEASE TELL ME I GOT IT CORRECT! I will go and cry if I don't. :(

Answer 70

you got it!! you are fine.

Answer 71

Ok. I think i can breathe now lol

Answer 72

While i am helping you, I wont let you fail...:) so breathe easy.

Answer 73

the next problem is....

Answer 74

I am eternally grateful!

Answer 75

Oh ok now time to stop breathing again....the problem said to solve:
S=p/3 (c +L)

Answer 76

PhiBee, keep breathing. also, did it tell you what variable to solve for?

Answer 77

Oh! Yeah it said solve for L. My lack of breathing made me forget haha

Answer 78

lol. Let me ask you something. During tests, do you sometimes blank an answer, even tho you know what to do?

Answer 79

Are you kidding me? All the time! my mind gets all fuzzy and I feel like I'm going to faint! :(