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

- September 5th 2011, 04:04 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? - September 5th 2011, 04:07 PMSironRe: Rearranging formulas
I would write:

- September 5th 2011, 04:16 PMDavid GreenRe: Rearranging formulas
- September 5th 2011, 04:18 PMSironRe: Rearranging formulas
Because:

-6c+c=-5c - September 5th 2011, 04:21 PMpickslidesRe: Rearranging formulas
- September 5th 2011, 04:28 PMDavid GreenRe: Rearranging formulas
- September 5th 2011, 04:33 PMpickslidesRe: Rearranging formulas
- September 5th 2011, 04:36 PMDavid GreenRe: Rearranging formulas
- September 5th 2011, 04:50 PMpickslidesRe: Rearranging formulas
I appreciate the honesty

__Spoiler__: - September 5th 2011, 04:54 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.

- September 5th 2011, 05:03 PMDavid GreenRe: Rearranging formulas
- September 6th 2011, 10:52 AMDavid GreenRe: Rearranging formulas
- September 6th 2011, 02:46 PMpickslidesRe: Rearranging formulas
You can't just remove the 'c'. This has made your working of the problem incorrect.

- September 6th 2011, 04:07 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 - September 7th 2011, 02:44 PMpickslidesRe: Rearranging formulas
Post PM

From this step:

We need to isolate by factoring, recall so

Now divide from both sides

All good?