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    Sorry I can't find the maths forum.
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    (Original post by sully50sully)
    Sorry I can't find the maths forum.
    A calculator is the easiest way.
    Alternatively: \dfrac{a}{b} \times \dfrac{c}{d} = \dfrac{ac}{bd}
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    (Original post by sully50sully)
    Sorry I can't find the maths forum.
    Erm, this is the maths forum.

    1/9\times 3/5 =\dfrac{1}{9}\times\dfrac{3}{5}=  \dfrac{1\times 3}{9\times 5}

    Can you now simplify (cancel as appropriate) and finish it?
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    (Original post by joostan)
    A calculator is the easiest way.
    Alternatively: \dfrac{a}{b} \times \dfrac{c}{d} = \dfrac{ac}{bd}
    I need to do it without a calculator for my exam, I got 3/45 but it's wrong on my maths
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    (Original post by sully50sully)
    I need to do it without a calculator for my exam, I got 3/45 but it's wrong on my maths
    It's correct so far, but you can cancel a factor from the top and bottom.
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    1/15

    do 3x1 for the numerator and 5x9 for the denominator and you get 3/45 you can simply after that
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    (Original post by yaboy)
    1/15

    do 3x1 for the numerator and 5x9 for the denominator and you get 3/45 you can simply after that
    how do you simplify after that to get 1/15?
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    (Original post by sully50sully)
    how do you simplify after that to get 1/15?
    As ghostwalker says, divide the top and bottom of the fraction by a common factor -
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    in this case 3.
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    (Original post by sully50sully)
    how do you simplify after that to get 1/15?

    On post 3 you can see 3 and 9 can cancel
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    (Original post by sully50sully)
    how do you simplify after that to get 1/15?
    It can be easier to simplify just after doing \frac{a}{b} \times \frac{c}{d} = \frac{a c}{b d}, but before actually calculating ac etc; in this case, \frac{1}{9} \times \frac35 = \frac{1\times 3}{9 \times 5} = \frac{1 \times 1}{3 \times 5} - do you see why?
 
 
 
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Updated: April 18, 2013
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