Rearranging the subject of an equation help please

  • Context: MHB 
  • Thread starter Thread starter sarannie
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Discussion Overview

The discussion revolves around the process of rearranging the equation abc/3 = c^2 + a(b + 2) to make b the subject. It involves algebraic manipulation and understanding of how to isolate variables in an equation.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant requests help with rearranging the formula to isolate b.
  • Another participant suggests expanding the brackets, moving terms with b to one side, and factoring out b.
  • A later reply confirms the approach and provides an expanded form of the equation, indicating the next steps to isolate b.
  • One participant expresses uncertainty about the next steps and considers clearing the fraction by multiplying by 3.

Areas of Agreement / Disagreement

Participants generally agree on the initial steps to rearrange the equation, but the discussion remains unresolved regarding the subsequent steps and the best approach to isolate b.

Contextual Notes

There are limitations in the discussion, such as missing assumptions about the values of variables and the dependence on the correct interpretation of algebraic manipulation steps.

sarannie
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Please please can you help me understand how to rearrange this formula to make b the subject:
abc/3=c^2+a(b+2)
 
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Start by expanding the brackets, moving every term that has a "b" to one side, and taking b out as a factor.
 
Prove It said:
Start by expanding the brackets, moving every term that has a "b" to one side, and taking b out as a factor.

Thank you, I have an absolute mental block with algebra.
So do I do a x b a x 2 next?
 
sarannie said:
Thank you, I have an absolute mental block with algebra.
So do I do a x b a x 2 next?

Hi there,

Yep, I think I know what you mean and if so that's the right idea. After expanding you'll get this:

$$\frac{abc}{3}=c^2+ab+2a$$

Now what you should do is collect the terms with a "$b$" in them on one side and terms without on the other. If you do that you'll get this:

$$\frac{abc}{3}-ab=c^2+2a$$

With me so far? Any idea what to do next?
 
You are very good to help me, thank you.
I'm wondering about clearing that fraction by multiplying by 3?
 

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