formual manipulation

A

account39

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I still don't have a formula for that works.

I need a formula to solve for 'a', given the formula

w = 100 / { [ ( 0.95a + 20.9) - 12 ] / c } + 1

I don't know how to do this sort of thing, I don't have a teacher, I'm an old guy & have forgotten most of the math I learned,
if you could help me, it would be appreciated.

thank you

ps Is there no way to delete my posts, or is it automatic after a certain period of time?
 
account39 said:
I still don't have a formula for that works.

I need a formula to solve for 'a', given the formula

w = 100 / { [ ( 0.95a + 20.9) - 12 ] / c } + 1

\(\displaystyle w \, = \, \frac{100}{\frac{0.95a + 20.9}{c}} + 1\)

\(\displaystyle w \, - \, 1 \, = \, \frac{100}{\frac{0.95a + 20.9}{c}}\)

\(\displaystyle w \, - \, 1 \, = \, \frac{100\cdot c}{0.95a + 20.9}\)

\(\displaystyle 0.95a + 20.9 \, = \, \frac{100\cdot c}{w \, - \, 1}\)

Can you continue from here?

Where did this problem come from? Are you taking a class - and this is homework?

I don't know how to do this sort of thing, I don't have a teacher, I'm an old guy & have forgotten most of the math I learned,
if you could help me, it would be appreciated.

thank you

ps Is there no way to delete my posts, or is it automatic after a certain period of time?

Why do you want to delete your post?
Click to expand...
 


I posted the following, at the other location you started to discuss this.

Can you tell me why this expression for a "does not work"?



You replaced 2 with c, while I was typing my post. (Heh, heh.)

Now we have the following.

\(\displaystyle a \;=\; \frac{105.26315789 \cdot c}{w} \;-\; 1.05263158 \cdot c \;-\; 9.36842105\)



As long as your post is the last post in the thread, you can delete it by clicking the [x] button, located to the left of the
button on the post in question.

Once somebody replies after your post, the [x] button is no longer available, and only a moderator can delete the particular post.

BTW, if you would like to continue a discussion that you've already started, we appreciate your responses in the same thread versus starting new threads.

Cheers ~ Mark 8-)
Click to expand...
 


Nevermind. I just realized that you've changed your equation again.

And, as I stated in the first discussion that you started, I'm assuming that you're not interested in learning "how" to solve for a; you just want the formula.

Here it is, based on your latest equation.

\(\displaystyle a \;=\; -0.10526316 \cdot \frac{89\,w \;-\; 1000\,c \;-\; 89}{w \;-\; 1}\)

When you scatter your thoughts across different locations, I get confused. Please stick to one thread per topic. 8-)

 
Thanks for all your efforts guys. I haven't used a bulleten board on the internet before and I've had a computer since 1987.
The reason I wanted to delete posts was because I kept getting the equation wrong. Believe it or not I used to be an A student in math, it was my favorite subject but I'm 62 now and never had a job that required algebra. So I am interested in seeing how the formula is maniulated. I don't know how you guys write your fractions so nice.
I've been trying to figure this out for 2 weeks now. Here is the right one, I need a formula for 'a' given the formula

w = 100 / [ ( ( 0.95 * ( a + c + 10 ) ) - ( c - 5 ) ) + 1 ]

This can be verified using these values: w = 14.54545, a = 1.5 and c = 1.
The value for 'a' can never be negative as the reason I'm doing this is I'm writing a computer program in Delphi to play Texas Hold'em online and 'a' is the number of bets already in the pot, do I call, raise or fold with my hand which has a 'w' (win percentage) and a 'c' cost. The rake is 5%.

Thanks again
 
account39 said:
w = 100 / [ ( ( 0.95 * ( a + c + 10 ) ) - ( c - 5 ) ) + 1 ]
This can be verified using these values: w = 14.54545, a = 1.5 and c = 1.
Click to expand...
For that to be correct, your (c - 5) has to be (c + 5).

Quit "bluffing" us :wink:
 
you went to all that trouble but you didn't help me, what did they call you? Dennis the menace? :?
 
account39 said:
you went to all that trouble but you didn't help me, what did they call you? Dennis the menace? :?
Click to expand...
That would be nice...but they call me much worse than that! But be NICE to your elders: I'm 67! :wink:
I wanted to settle the (c - 5) : (c + 5) thing before doing anything.

OK; so your equation is:
w = 100 / [ ( ( 0.95 * ( a + c + 10 ) ) - ( c + 5 ) ) + 1 ]
and you want to solve for a.

To start, since the multiplication by .95 affects (a + c + 10) only, then
there is no need to bracket the (c + 5); the -(c + 5) + 1 can be shown as: - c - 4 ;
so equation can be changed to :
w = 100 / [0.95( a + c + 10 ) - c - 4] ; gee, don't you already feel less confused?

Next (not really necessary, but I find makes things easier) get rid of decimals by
multiplying numerator and denominator by 100:
w = 10000 / [95(a + c + 10) - 100c - 400] ; how does that grab you?

Do the multiplication by 95:
w = 10000 / (95a + 95c + 950 - 100c - 400) ; yea: got rid of another set of brackets!

Simplify:
w = 10000 / (95a - 5c + 550)

Get rid of fraction:
w(95a - 5c + 550) = 10000

Divide by 5 (always good idea to reduce as much as possible):
w(19a - c + 110) = 2000

Do the multiplication:
19aw - cw + 110w = 2000

Isolate the term with "a":
19aw = cw - 110w + 2000

Wrap up:
a = (cw - 110w + 2000) / (19w) ; there ya go...

If instead you wanted to solve for c, from here:
19aw - cw + 110w = 2000

Isolate the terms with c:
cw = 19aw + 110w - 2000

wrap up:
c = (19aw + 110w - 2000) / w

Hope that helps you out, old man :idea:
 
I don't think that's right. I get a = 13.07917353 and it is supposed to be 1.5.
I think the grouping is correct if you type it into a calculator but you dropped a parenthesis.

w = 100 / ( ( 0.95 * ( a + c + 10 ) ) - c - 5 ) + 1

we are so close, just a little more............please
 
Denis said:
account39 said:
you went to all that trouble but you didn't help me, what did they call you? Dennis the menace? :?
Click to expand...
That would be nice...but they call me much worse than that! But be NICE to your elders: I'm 67! :wink:
I wanted to settle the (c - 5) : (c + 5) thing before doing anything.

OK; so your equation is:
w = 100 / [ ( ( 0.95 * ( a + c + 10 ) ) - ( c + 5 ) ) + 1 ]
and you want to solve for a.

To start, since the multiplication by .95 affects (a + c + 10) only, then
there is no need to bracket the (c + 5); the -(c + 5) + 1 can be shown as: - c - 4 ;
so equation can be changed to :
w = 100 / [0.95( a + c + 10 ) - c - 4] ; gee, don't you already feel less confused?

Next (not really necessary, but I find makes things easier) get rid of decimals by
multiplying numerator and denominator by 100:
w = 10000 / [95(a + c + 10) - 100c - 400] ; how does that grab you?

Do the multiplication by 95:
w = 10000 / (95a + 95c + 950 - 100c - 400) ; yea: got rid of another set of brackets!

Simplify:
w = 10000 / (95a - 5c + 550)

Get rid of fraction:
w(95a - 5c + 550) = 10000

Divide by 5 (always good idea to reduce as much as possible):
w(19a - c + 110) = 2000

Do the multiplication:
19aw - cw + 110w = 2000

Isolate the term with "a":
19aw = cw - 110w + 2000

Wrap up:
a = (cw - 110w + 2000) / (19w) ; there ya go...

If instead you wanted to solve for c, from here:
19aw - cw + 110w = 2000

Isolate the terms with c:
cw = 19aw + 110w - 2000

wrap up:
c = (19aw + 110w - 2000) / w

Hope that helps you out, old man :idea:
Click to expand...
Denis:

You typed up all these???!!! :shock: :shock: :shock: :shock:
 
awesome old man, I knew you could do it

I have saved the page so you can delete both of my topics

thanks a lot
 
account39 said:
I don't think that's right. I get a = 13.07917353 and it is supposed to be 1.5.
Click to expand...
Huh? I gave you: a = (cw - 110w + 2000) / (19w)

c = 1, w = 14.545...

cw - 110w + 2000 = 1*14.545 - 110*14.545 + 2000 = 414.595...

19w = 19*14.545 = 276.355...

414.595 / 276.355 = 1.500226....
 
Subhotosh Khan said:
Denis:
You typed up all these???!!! :shock: :shock: :shock: :shock:
Click to expand...
Had a moment of weakness. Solemn promise it won't happen for a good while :idea:
 
account39 said:
… The reason I wanted to delete posts was because I kept getting the equation wrong …
Click to expand...


Ahh. That's what the [Edit] button is for. It's easy to edit posts, but be sure to include descriptive notations to draw our attention to the changes (lest our old, tired eyes miss them).

Using colors is great for calling attention to changes. Posting a note at the end of the thread to alert us to edits is also a good idea.

OR, you can simply post the correct information as an addition, and then advise us to ignore any previous posts.

Your choice.

Finally, the more information that you provide about your situation UP FRONT, the sooner you will get back useful responses. For example, try to make clear exactly what you expect. (I'm still not sure if you're trying to learn algebra versus simply getting missing pieces to fill in your computer programming project.) 8-)

 
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