Prove that if ${7k:kin{mathbb Z}}subsetneq{nm:min{mathbb Z}}$, then $n=1.$












0












$begingroup$


Let n be a natural number. Prove that if ${7k:kin{mathbb Z}}subsetneq{nm:min{mathbb Z}}$, then $n=1$.



I know that we must show $xin{A}$ implies $xin{B}$, and that there exists $xin{B}$ such that $xnotin{A}$, which means that $xin{A}neq{xin{B}}$.
Any help is appreciated; thanks










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    Let n be a natural number. Prove that if ${7k:kin{mathbb Z}}subsetneq{nm:min{mathbb Z}}$, then $n=1$.



    I know that we must show $xin{A}$ implies $xin{B}$, and that there exists $xin{B}$ such that $xnotin{A}$, which means that $xin{A}neq{xin{B}}$.
    Any help is appreciated; thanks










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Let n be a natural number. Prove that if ${7k:kin{mathbb Z}}subsetneq{nm:min{mathbb Z}}$, then $n=1$.



      I know that we must show $xin{A}$ implies $xin{B}$, and that there exists $xin{B}$ such that $xnotin{A}$, which means that $xin{A}neq{xin{B}}$.
      Any help is appreciated; thanks










      share|cite|improve this question











      $endgroup$




      Let n be a natural number. Prove that if ${7k:kin{mathbb Z}}subsetneq{nm:min{mathbb Z}}$, then $n=1$.



      I know that we must show $xin{A}$ implies $xin{B}$, and that there exists $xin{B}$ such that $xnotin{A}$, which means that $xin{A}neq{xin{B}}$.
      Any help is appreciated; thanks







      proof-writing






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Feb 3 at 1:20









      Andrés E. Caicedo

      66k8160252




      66k8160252










      asked Feb 2 at 21:22









      macymacy

      526




      526






















          2 Answers
          2






          active

          oldest

          votes


















          1












          $begingroup$

          The inclusion provided says that if $x$ is a multiple of $7$, then $x$ is a multiple of $n$. Moreover, $n neq 7$, else the two sets are equal, but it's specified that they are not. Use your knowledge of the unique prime factorisation of $7$ to conclude.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Ah I see what you are saying! Thanks so much.
            $endgroup$
            – macy
            Feb 2 at 21:47










          • $begingroup$
            Key thing to take away: to divide is to contain (as Bill shows in symbols in his answer). As for proof writing, I hope you tried different things before you posted on here. I know I started off my answer by assuming $x in 7mathbb{Z}$, and seeing what happened, and it didn't quite work out, so I thought about why and started again. You should go through a similar process.
            $endgroup$
            – bounceback
            Feb 2 at 22:13



















          0












          $begingroup$

          Hint $ $ Show $ aBbb Zsupseteq bBbb Ziff amid b. $ Hence $,nBbb Zsupseteq 7Bbb Ziff nmid 7$






          share|cite|improve this answer









          $endgroup$














            Your Answer








            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "69"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            autoActivateHeartbeat: false,
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            noCode: true, onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3097814%2fprove-that-if-7kk-in-mathbb-z-subsetneq-nmm-in-mathbb-z-then-n%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            2 Answers
            2






            active

            oldest

            votes








            2 Answers
            2






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            1












            $begingroup$

            The inclusion provided says that if $x$ is a multiple of $7$, then $x$ is a multiple of $n$. Moreover, $n neq 7$, else the two sets are equal, but it's specified that they are not. Use your knowledge of the unique prime factorisation of $7$ to conclude.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              Ah I see what you are saying! Thanks so much.
              $endgroup$
              – macy
              Feb 2 at 21:47










            • $begingroup$
              Key thing to take away: to divide is to contain (as Bill shows in symbols in his answer). As for proof writing, I hope you tried different things before you posted on here. I know I started off my answer by assuming $x in 7mathbb{Z}$, and seeing what happened, and it didn't quite work out, so I thought about why and started again. You should go through a similar process.
              $endgroup$
              – bounceback
              Feb 2 at 22:13
















            1












            $begingroup$

            The inclusion provided says that if $x$ is a multiple of $7$, then $x$ is a multiple of $n$. Moreover, $n neq 7$, else the two sets are equal, but it's specified that they are not. Use your knowledge of the unique prime factorisation of $7$ to conclude.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              Ah I see what you are saying! Thanks so much.
              $endgroup$
              – macy
              Feb 2 at 21:47










            • $begingroup$
              Key thing to take away: to divide is to contain (as Bill shows in symbols in his answer). As for proof writing, I hope you tried different things before you posted on here. I know I started off my answer by assuming $x in 7mathbb{Z}$, and seeing what happened, and it didn't quite work out, so I thought about why and started again. You should go through a similar process.
              $endgroup$
              – bounceback
              Feb 2 at 22:13














            1












            1








            1





            $begingroup$

            The inclusion provided says that if $x$ is a multiple of $7$, then $x$ is a multiple of $n$. Moreover, $n neq 7$, else the two sets are equal, but it's specified that they are not. Use your knowledge of the unique prime factorisation of $7$ to conclude.






            share|cite|improve this answer









            $endgroup$



            The inclusion provided says that if $x$ is a multiple of $7$, then $x$ is a multiple of $n$. Moreover, $n neq 7$, else the two sets are equal, but it's specified that they are not. Use your knowledge of the unique prime factorisation of $7$ to conclude.







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Feb 2 at 21:33









            bouncebackbounceback

            446212




            446212












            • $begingroup$
              Ah I see what you are saying! Thanks so much.
              $endgroup$
              – macy
              Feb 2 at 21:47










            • $begingroup$
              Key thing to take away: to divide is to contain (as Bill shows in symbols in his answer). As for proof writing, I hope you tried different things before you posted on here. I know I started off my answer by assuming $x in 7mathbb{Z}$, and seeing what happened, and it didn't quite work out, so I thought about why and started again. You should go through a similar process.
              $endgroup$
              – bounceback
              Feb 2 at 22:13


















            • $begingroup$
              Ah I see what you are saying! Thanks so much.
              $endgroup$
              – macy
              Feb 2 at 21:47










            • $begingroup$
              Key thing to take away: to divide is to contain (as Bill shows in symbols in his answer). As for proof writing, I hope you tried different things before you posted on here. I know I started off my answer by assuming $x in 7mathbb{Z}$, and seeing what happened, and it didn't quite work out, so I thought about why and started again. You should go through a similar process.
              $endgroup$
              – bounceback
              Feb 2 at 22:13
















            $begingroup$
            Ah I see what you are saying! Thanks so much.
            $endgroup$
            – macy
            Feb 2 at 21:47




            $begingroup$
            Ah I see what you are saying! Thanks so much.
            $endgroup$
            – macy
            Feb 2 at 21:47












            $begingroup$
            Key thing to take away: to divide is to contain (as Bill shows in symbols in his answer). As for proof writing, I hope you tried different things before you posted on here. I know I started off my answer by assuming $x in 7mathbb{Z}$, and seeing what happened, and it didn't quite work out, so I thought about why and started again. You should go through a similar process.
            $endgroup$
            – bounceback
            Feb 2 at 22:13




            $begingroup$
            Key thing to take away: to divide is to contain (as Bill shows in symbols in his answer). As for proof writing, I hope you tried different things before you posted on here. I know I started off my answer by assuming $x in 7mathbb{Z}$, and seeing what happened, and it didn't quite work out, so I thought about why and started again. You should go through a similar process.
            $endgroup$
            – bounceback
            Feb 2 at 22:13











            0












            $begingroup$

            Hint $ $ Show $ aBbb Zsupseteq bBbb Ziff amid b. $ Hence $,nBbb Zsupseteq 7Bbb Ziff nmid 7$






            share|cite|improve this answer









            $endgroup$


















              0












              $begingroup$

              Hint $ $ Show $ aBbb Zsupseteq bBbb Ziff amid b. $ Hence $,nBbb Zsupseteq 7Bbb Ziff nmid 7$






              share|cite|improve this answer









              $endgroup$
















                0












                0








                0





                $begingroup$

                Hint $ $ Show $ aBbb Zsupseteq bBbb Ziff amid b. $ Hence $,nBbb Zsupseteq 7Bbb Ziff nmid 7$






                share|cite|improve this answer









                $endgroup$



                Hint $ $ Show $ aBbb Zsupseteq bBbb Ziff amid b. $ Hence $,nBbb Zsupseteq 7Bbb Ziff nmid 7$







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Feb 2 at 22:08









                Bill DubuqueBill Dubuque

                214k29197659




                214k29197659






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Mathematics Stack Exchange!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    Use MathJax to format equations. MathJax reference.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3097814%2fprove-that-if-7kk-in-mathbb-z-subsetneq-nmm-in-mathbb-z-then-n%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    MongoDB - Not Authorized To Execute Command

                    in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

                    How to fix TextFormField cause rebuild widget in Flutter