Rearranging Formula: Make e the Subject | 10b + 5be - 3e + 7c

In summary, the individual needs to use parentheses and make sure their starting equation is set equal to zero in order to correctly rearrange the formula to make e the subject.
  • #1
Gringo123
141
0
I need to rearrange this formula to make e the subject. Have I done it correctly?

10b + 5be - 3e + 7c
10b + 5be - 3e = 7c
5be - 3e = 7c - 10b
e(5b - 3) = 7c - 10b

e = 7c - 10b / 5b - 3
 
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  • #2
Gringo123 said:
I need to rearrange this formula to make e the subject. Have I done it correctly?
You're not starting with an equation! Without the first line below being an equation, you can't solve for anything.
Gringo123 said:
10b + 5be - 3e + 7c
10b + 5be - 3e = 7c
5be - 3e = 7c - 10b
e(5b - 3) = 7c - 10b

e = 7c - 10b / 5b - 3
Assuming that this is your starting equation -- 10b + 5be - 3e = 7c -- your work following it is fine, EXCEPT that you need to use parentheses. You should write e this way:
e = (7c - 10b) / (5b - 3)
 
  • #3
Thanks a lot Mark
 
  • #4
Mark44 said:
You're not starting with an equation! Without the first line below being an equation, you can't solve for anything.

Assuming that this is your starting equation -- 10b + 5be - 3e = 7c -- your work following it is fine, EXCEPT that you need to use parentheses. You should write e this way:
e = (7c - 10b) / (5b - 3)

Well if we assume that the first line is an equation (set equal to zero): 10b + 5be - 3e + 7c=0, then the second line changes:

10b + 5be - 3e = -7c, and that would change the rest of the steps which follow...
 

1. How do I make "e" the subject of the formula?

To make "e" the subject of the formula, we need to isolate it on one side of the equation by moving all other terms to the other side. This can be done by using basic algebraic operations such as addition, subtraction, multiplication, and division.

2. What is the purpose of rearranging a formula?

Rearranging a formula allows us to solve for a specific variable or unknown value. It also makes it easier for us to manipulate and use the formula in different situations.

3. Can we rearrange a formula in any way we want?

No, we cannot rearrange a formula in any way we want. We need to follow the rules of algebra and maintain the equality of the equation. This means that whatever operation we do to one side of the equation, we must also do to the other side.

4. What is the first step in rearranging a formula?

The first step in rearranging a formula is to identify the variable that we want to make the subject. Then, we need to move all other terms to the other side of the equation using algebraic operations until the variable is isolated on one side.

5. Can we use the same method to rearrange any formula?

Yes, we can use the same method to rearrange any formula as long as we follow the rules of algebra and maintain the equality of the equation. However, the specific steps may vary depending on the complexity of the formula.

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