Results 1 to 6 of 6

Math Help - X:X?

  1. #1
    Newbie
    Joined
    Nov 2010
    Posts
    4

    Question X:X?

    Hi there,

    I have never really done sets before and I am trying to understand the notations etc. Any how would I be correct in assuming that where it says x:x is exactly divisible by 3 and x:x is exactly divisible by 7 that it means that its a set that consists of all the numbers in set A that are divisible by 3 , and by 7?


    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,790
    Thanks
    1687
    Awards
    1
    The set \mathcal{C} is read “set of all x such that x is exactly divisible by 7”.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Nov 2010
    Posts
    4
    Quote Originally Posted by Plato View Post
    The set \mathcal{C} is read “set of all x such that x is exactly divisible by 7”.
    So does that mean that the set of all x is a? And that set C is those in A that divide exactly by 7?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,790
    Thanks
    1687
    Awards
    1
    Quote Originally Posted by monkeyhead View Post
    So does that mean that the set of all x is a? And that set C is those in A that divide exactly by 7?
    No, the universe is \mathcal{E} not \mathcal{A}.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Nov 2010
    Posts
    4
    So C is all numbers between 1 and 25 that divide exactly by 7?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,790
    Thanks
    1687
    Awards
    1
    Well yes.
    Better put as: The set of all integers from 1 to 25 exactly divisible by 7.
    Follow Math Help Forum on Facebook and Google+


/mathhelpforum @mathhelpforum