a = 5b - 2c(3+b) + c make b the subject

a = 5b - 6c + b + c

b = 5b + 6c^2 / a

can I not do that?

Printable View

- Sep 5th 2011, 03:04 PMDavid GreenRearranging formulas
a = 5b - 2c(3+b) + c make b the subject

a = 5b - 6c + b + c

b = 5b + 6c^2 / a

can I not do that? - Sep 5th 2011, 03:07 PMSironRe: Rearranging formulas
I would write:

- Sep 5th 2011, 03:16 PMDavid GreenRe: Rearranging formulas
- Sep 5th 2011, 03:18 PMSironRe: Rearranging formulas
Because:

-6c+c=-5c - Sep 5th 2011, 03:21 PMpickslidesRe: Rearranging formulas
- Sep 5th 2011, 03:28 PMDavid GreenRe: Rearranging formulas
- Sep 5th 2011, 03:33 PMpickslidesRe: Rearranging formulas
- Sep 5th 2011, 03:36 PMDavid GreenRe: Rearranging formulas
- Sep 5th 2011, 03:50 PMpickslidesRe: Rearranging formulas
I appreciate the honesty

__Spoiler__: - Sep 5th 2011, 03:54 PMSironRe: Rearranging formulas
Sorry David, I didn't see that the first term had also a facor b so what I wrote doesn't make sense, pickslides solution is the good one.

- Sep 5th 2011, 04:03 PMDavid GreenRe: Rearranging formulas
- Sep 6th 2011, 09:52 AMDavid GreenRe: Rearranging formulas
- Sep 6th 2011, 01:46 PMpickslidesRe: Rearranging formulas
You can't just remove the 'c'. This has made your working of the problem incorrect.

- Sep 6th 2011, 03:07 PMDavid GreenRe: Rearranging formulas
Hi Pickslides

Please advise what you did to loose a C in your first line?

The original equation was;

a = 5b - 2c (3 + b) + C

In my first line of working out I got;

a = 5b - 6c - 2bc + c

in your first line of working out you got;

a = 5b - 6c -2bc

what did you do with the latter C ?

The final answer I am sure you had;

b = 4b - 5c / a - c

what changed?

Thanks

David - Sep 7th 2011, 01:44 PMpickslidesRe: Rearranging formulas
Post PM

From this step:

We need to isolate by factoring, recall so

Now divide from both sides

All good?