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C2 help

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    3 - 75/x^2=0
    can somone help me solve this, its something i should be able to do but i cant get my mind around it.
    this is what i should get x=5
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    (Original post by djmans)
    3 - 75/x^2=0
    can somone help me solve this, its something i should be able to do but i cant get my mind around it.
    this is what i should get x=5
    You could move the second term over to the right hand side to give

     3 = \frac{75}{x^2} and then try to get the x^2 on its own and work from there.
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    (Original post by SeanFM)
    You could move the second term over to the right hand side to give

     3 = \frac{75}{x^2} and then try to get the x^2 on its own and work from there.
    Ive got a problem if you could help mee too
    √ 7
    --------
    3-√ 7
    Simplifying in surds
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    (Original post by harrxful)
    Ive got a problem if you could help mee too
    √ 7
    --------
    3-√ 7
    Simplifying in surds
    When you want to simplify a surd of that form, what do you usually tend to do with the denominator?
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    (Original post by SeanFM)
    When you want to simplify a surd of that form, what do you usually tend to do with the denominator?
    times all of it by the denominatior
    √ 7
    --------
    3-√7


    *
    √ 7
    ----
    √ 7
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    (Original post by harrxful)
    times all of it by the denominatior
    √ 7
    --------
    3-√7


    *
    √ 7
    ----
    √ 7
    I know what you're trying to say but you actually have to rationalise it. Since the denominator is  3 - \sqrt7, \mathrm{you\ have\ to\ multiply\ it\ by} \frac{3 + \sqrt7}{3 + \sqrt7}
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    (Original post by SeanFM)
    I know what you're trying to say but you actually have to rationalise it. Since the denominator is  3 - \sqrt7, \mathrm{you\ have\ to\ multiply\ it\ by} \frac{3 + \sqrt7}{3 + \sqrt7}
    I spent like 5 minutes trying to analyse where I went wrong
    thanks man hopefully I can learn from that now
 
 
 
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