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Rearranging equations help, GCSEs were a decade ago Watch

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    Hello,

    I went back into education after a while away and I need help with rearranging equations. Here is the example I'm trying to rearrange:
    R/r = sqrt(f+p)/(f-p)
    Attachment 694548
    I need to rearrange for f.

    So far this is what I've done:
    Name:  kkjnjhfd.PNG
Views: 11
Size:  2.0 KB

    I have tried to move forward in various ways and none of them work. I actually managed to get rid of f somehow which is clearly not ideal. Any help would be appreciated but I really need some detailed advice. I can't continue to spend hours rearranging things and getting nowhere.
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    Next multiply both sides by r^2. Expand the brackets, then collect f terms on one side of the equals sign.

    Let me know if u have any more questions or need further help
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    (Original post by whatever24)
    So far this is what I've done:
    Name:  kkjnjhfd.PNG
Views: 11
Size:  2.0 KB
    I could be missing something here but you've literally done it? now all you have to do is subtract p from both sides and you have f on it's own = the rest of the equation ???????
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    (Original post by econflower)
    I could be missing something here but you've literally done it? now all you have to do is subtract p from both sides and you have f on it's own = the rest of the equation ???????
    Assuming the OP need some to make f the subject, you can't have f on both sides of the equation.
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    (Original post by Notnek)
    Assuming the OP need some to make f the subject, you can't have f on both sides of the equation.
    How did i manage to miss seeing the f on the left?! haha my bad
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    Name:  20171007_175028.jpg
Views: 12
Size:  521.2 KBfrom what you've done
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    f =[p(r^2+R^2)]/(R^2-r^2)
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    Thank you everyone! Thank you for replying so quickly as well
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    A reminder to everyone : full solutions are not allowed in the maths forum. Please read the posting guidelines at the top of the forum. Thanks.
 
 
 
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