Rearranging a formula
Maths and statistics discussion, revision, exam and homework help.
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Re: Rearranging a formulaIts not allowed to post full solutions.(Original post by krisshP)
For the formula:
I have to make a the subject. What is the right answer? Please explain HOW you get the correct answer with working out. Thanks.
I got:
a=8-4c
44-----
444b-c
But I got the wrong answer
Can you show your working, then i can tell you where you went wrong. -
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Re: Rearranging a formulaYou forgot to multiply ab by 4 when getting rid of the fraction.(Original post by krisshP)
For the formula:
I have to make a the subject. What is the right answer? Please explain HOW you get the correct answer with working out. Thanks.
I got:
a=8-4c
44-----
444b-c
But I got the wrong answer
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Re: Rearranging a formulawhen multiplying ab by 4 I get a wrong answer of
8-4c
-------=a
4b-c
Here I first multiplied by 4 and expanded to get:
4ab-ca+4c=8
Then I -4c to get:
4ab-ca=8-4c
After this I factorised the LHS to get:
a(4b-c)=8-4c
Then I divided both sides by (4b-c) to get the answer stated above.
WHY did I fail? -
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Re: Rearranging a formulaWhat is the final answer supposed to be?(Original post by krisshP)
when multiplying ab by 4 I get a wrong answer of
8-4c
-------=a
4b-c
Here I first multiplied by 4 and expanded to get:
4ab-ca+4c=8
Then I -4c to get:
4ab-ca=8-4c
After this I factorised the LHS to get:
a(4b-c)=8-4c
Then I divided both sides by (4b-c) to get the answer stated above.
WHY did I fail? -
- Reputation:
- TSR Demigod
- Posts: 5,512
Re: Rearranging a formula(Original post by krisshP)
when multiplying ab by 4 I get a wrong answer of
8-4c
-------=a
4b-c
Here I first multiplied by 4 and expanded to get:
4ab-ca+4c=8
Then I -4c to get:
4ab-ca=8-4c
After this I factorised the LHS to get:
a(4b-c)=8-4c
Then I divided both sides by (4b-c) to get the answer stated above.
WHY did I fail?
Multiply throughout by 4,
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Re: Rearranging a formulaI have indicated your mistake in my previous post.(Original post by krisshP)
Not sure but I know that the answer of:
8-4c
------ = a
4b-c
is wrong.
What answer do you get? Is it the same as if it is it could mean that mymaths is wrong.
