Question

Is this right?
Q: Solve
13+s/p=2 for p
A: p(13)=2(13)+2=28?
What is s? Ill say 2.
28/13≈2.15

Answer 1

nope

Answer 2

Which part isnt right?

Answer 3

Goddammit this is just hopeless..

Answer 4

hi Inopeki
do not despair!
practice practice...

Answer 5

what made you feel like putting a 13 there?
we were supposed to get a function like before

Answer 6

And didnt i?

Answer 7

you can't start plotting points like that until we've solved it for one of the variables. The answer to the question I was looking for should have 2 variables.

Answer 8

13+s/p=2
what do you get multiplying both sides by p?
do nothing else but that.

Answer 9

I can go check

Answer 10

no, I was wrong, nevermind

Answer 11

13+s/p=2 for p
11+s/p=0
11=-s/p
p=-s/11

Answer 12

See? This guy knows it. Why cant i?

Answer 13

Whatever. give me a new one

Answer 14

You can with Time Inopeki

Answer 15

well, there's one way.
btw Rhauckus I made up this problem for Inopeki to teach him how to solve for a variable
@Inopeki, he has many years doing this, you need to practice basics. It will be like that for a while.

Answer 16

Well that sucks.. Still, if i really need to learn this i guess i will. Give me a new example so i can practise please

Answer 17

a new one?
solve\[A=2\pi r h\] for A, r, and h
I need to get you to stop thinking in numbers.

Answer 18

that's three problems, by the way.

Answer 19

is \[\pi\] 3.14 here or is it a variable?

Answer 20

no, it's about 3.14159..., that's why I didn't make it something to solve for.
but don't think of it as a number, leave it as pi. The number does not matter.

Answer 21

A=2(pi)rh

Answer 22

Ok, so the answer should not be a number?

Answer 23

not at all

Answer 24

Interesting..

Answer 25

it should be a function like
r=5t+4
it has some numbers, but not all.

Answer 26

One question. If i, in the answer have to give you As "definition", how can that not be a number?

Answer 27

The formula I gave you is for the surface area of the side of a cylinder. The surface area of any particular cylinder depends on its radius and length.
So the formula covers all possible cylinders, but only for some particular cylinders will you get a certain value for the surface area. It is a function, this time of both r and h.

Answer 28

if I tell you the radius and height of our particular cylinder, only then can you get a number.

Answer 29

I just studied that in school! I thought we were talking algebra here..

Answer 30

@Turning you train guys well I will need your help for multivariable calculus, Laplace and stuff I will let you know then :D Great job is all I can say :D

Answer 31

Solving for a variable is algebra. They are all connected as you will learn.

Thanks Akshay!

Answer 32

But that still doesnt answer my question, how should i define A?

Answer 33

in this case, A is already defined by\[A=2\pi rh\]that is basically the definition of the surface area of the side of a circular cylinder.
No more definition is needed.
I wanted you to catch that the first problem, solve for A, is already done for you:
we already have A=(something)
so it IS solved for A.
So now solve it for r, if you can.
what can we divide by to get r by itself?

Answer 34

We can divide h with A, right?

Answer 35

No.. that cant be it.

Answer 36

when you say 'divide h with A'
I'm not sure what you mean. Do you mean
divide both sides by A
or divide both sides by h
???
One is okay, one is not.
You know that division is the inverse of multiplication. So ask yourself 'what is r being multiplied by?' and divide by that.
Well, what is r being multiplied by?

Answer 37

The height.

Answer 38

is that all?

Answer 39

Actually no

Answer 40

what else?

Answer 41

pi^2

Answer 42

right?

Answer 43

where did you see a squared term?

Answer 44

I have no idea.. i realize thats wrong now cause that is for getting the volume of a cylinder..

Answer 45

And that concludes that i am an utter and complete retard

Answer 46

it's okay.
so again, what, in all, is r being multiplied by?

Answer 47

c'mon, being hard on yourself never helped anything.

Answer 48

2 and then pi

Answer 49

and...?

Answer 50

height?

Answer 51

wait!

Answer 52

right, it's being multiplied by
2(pi)h
so that is what we need to divide by
no don;t take it back!

Answer 53

if you divide both sides by h, and both sides by pi you should isolate it so you have 2r, right?

Answer 54

true!

Answer 55

Yeah.. pretty much what you said

Answer 56

But that doesnt mathematically give us anything..

Answer 57

Then you just divide both sides by 2 and get r

Answer 58

sure it does, it gives us the answer
not all answers in math are numbers, in fact I hate using numbers if I can help it.
about your last post, yes, so what do we get for
r=?

Answer 59

What do you mean?

Answer 60

what is on the other side of the equation when we solve for r?

Answer 61

what did we divide both sides by?

Answer 62

2(åi)h?

Answer 63

(pi)*

Answer 64

right. so what will A be divided by?

Answer 65

well we get r on both sides right?

Answer 66

2(pi)h

Answer 67

no, just one and all alone, that's what it means to solve for r
again, yes to your last post
so write out
r=...?

Answer 68

1

Answer 69

where did you get 1 ?

Answer 70

Nevermind, my mind is messing up my mind, if you know what i mean

Answer 71

If you are tired then take a break

here is the answer, watch is closely:
\[A=2\pi rh\]divide both sides by\[2\pi h\]giving\[r=\frac{A}{2\pi h}\]If you want to keep going then try just something simpler with NO numbers:\[ab=c\]solve for a

Answer 72

Maybe i should catch some sleep, its 4:50 am here..

Answer 73

that is a very good idea then.
sleep on it and try it in the morning. I can't tell you how many problems I've solved just by sleeping on them.
Don't worry, step-by-step. You will get there I know.
Goodnight!

Answer 74

Good night, thank you for all the help!

Answer 75

anytime :)

Answer 76

A=2πrh
divide both sides by
2πh
giving
r=A2πh
If you want to keep going then try just something simpler with NO numbers:
ab=c
solve for a

When you say "solve for a", do you mean i should isolate it?
I guess we would divide both sides by b and then c.

Answer 77

Actually, just b.

Answer 78

I would then get a/b=c/b
Simplified, a=c/b

Answer 79

^^^correct!
now get some sleep dude!
the mind needs to be fresh.

Answer 80

I did sleep, that answer was today.

Answer 81

lol I thought you stayed up all night.
Told you sleeping on it would help.
now solve
ab=c
for b

Answer 82

Thats easy, both sides divided by a, you get b/a=c/a
Simplify: b=c/a

Answer 83

no!

Answer 84

yes^^

Answer 85

actually, yes

Answer 86

that's what I wanted to hear
since it's so easy
A=2πrh
for r

Answer 87

Divide both sides with 2(pi)h, you get A/2(pi)h=2(pi)rh/2(pi)h
Simplified: A/2(pi)h=r

Answer 88

awesome!
I know you got it but you should write it as
A/(2π)h=r
parentheses make it clear what is on the bottom.

Answer 89

Yes!
Oh ok.

Answer 90

sorry, meant
A/(2πh)=r

Answer 91

anyway, slightly different one:
solve
5t=t/2+s
for s, then for t

Answer 92

So the whole bottom part in parenthesis?

Answer 93

that's two problems^^^

Answer 94

Multiply both sides by 2+s, right?

Answer 95

right, because everything in parentheses is on the bottom
if you wrote 1/2x I don't know whether you mean\[\frac{1}{2x}\]or\[\frac{1}{2}x\]so parentheses are nice to clear things up
think you can do the other?
solve
\[5t=\frac{t}{2}+s\]
for s
a good first step is to subtract t/2 from both sides. Then s will be isolated, right?

Answer 96

Oh, i thought you meant t/(2+s)

Answer 97

I would have used parentheses if I meant that. if I had meant that then you would have been right, so you'll get one like that soon.
but for now solve it as it is for s

Answer 98

Right, so now i have 5t-t/2=s, am i right?