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I dont get the end of this Chemistry sum

Comments

  • #2
    eoins2345
    Closed Accounts Posts: 154 ✭✭eoins2345


    just cross multiply ie x=7.07(2-x)
    x=14.14-7.07x
    8.07x=14.14
    x=1.75


  • #3
    damienricefan
    Registered Users, Registered Users 2 Posts: 165 ✭✭damienricefan


    eoins2345 wrote: »
    just cross multiply ie x=7.07(2-x)
    x=14.14-7.07x
    8.07x=14.14
    x=1.75

    but answer is 1.56???? still that looks wonderful for getting marks thanks :D


  • #4
    zodac
    Registered Users, Registered Users 2 Posts: 555 ✭✭✭zodac


    damienricefan wrote: »
    but answer is 1.56???? still that looks wonderful for getting marks thanks :D

    Slight miscalculation there. Ok,

    you start with x/(2-x)/2... you can bring the 2 up 2 levels so you get 2x/(2-x) (since dividing by 1/2 is like multiplying by 2)

    so now you cross multiply to get 2x=7.07(2-x)
    2x=14.14-7.07x
    9.07x=14.14
    x=1.5589
    x=1.56


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