PME Journal 1:9; is there any justification for solving linear linear equation with this method?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
2
down vote

favorite












In the PME Journal volume 1, issue 9, archived in here, in page 359 it is given that



enter image description here



However, is there any justification for solving system of linear equation with this method ?



The author only provides some examples for this method in the continuation of the article, and there is not even a word why this method works.







share|cite|improve this question

























    up vote
    2
    down vote

    favorite












    In the PME Journal volume 1, issue 9, archived in here, in page 359 it is given that



    enter image description here



    However, is there any justification for solving system of linear equation with this method ?



    The author only provides some examples for this method in the continuation of the article, and there is not even a word why this method works.







    share|cite|improve this question























      up vote
      2
      down vote

      favorite









      up vote
      2
      down vote

      favorite











      In the PME Journal volume 1, issue 9, archived in here, in page 359 it is given that



      enter image description here



      However, is there any justification for solving system of linear equation with this method ?



      The author only provides some examples for this method in the continuation of the article, and there is not even a word why this method works.







      share|cite|improve this question













      In the PME Journal volume 1, issue 9, archived in here, in page 359 it is given that



      enter image description here



      However, is there any justification for solving system of linear equation with this method ?



      The author only provides some examples for this method in the continuation of the article, and there is not even a word why this method works.









      share|cite|improve this question












      share|cite|improve this question




      share|cite|improve this question








      edited Jul 21 at 3:50
























      asked Jul 21 at 3:43









      onurcanbektas

      3,0611834




      3,0611834




















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          3
          down vote



          accepted










          They are (essentially) using a 'multiply and subtract' technique to simplify the equations.



          E.g. Multiply 1) by $d_2$ and 2) by $d_1$. Subtract and you get 4).



          You get 5) analogously with $d_3$ and $d_2$ on 2) and 3). Then, using the same idea, multiply 4) by $A_2$ and 5) by $A_1$, subtract and you get



          $$|A_1B_2|y + |A_1C_2|z = 0$$



          whence $fracyz = fracA_1B_2$ or $y:z = -|A_1C_2|:|A_1B_2|$.



          The same thing again gives the proportion for $x$. Once you have the proportions, you can substitute and solve for the values if necessary.






          share|cite|improve this answer





















            Your Answer




            StackExchange.ifUsing("editor", function ()
            return StackExchange.using("mathjaxEditing", function ()
            StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
            StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
            );
            );
            , "mathjax-editing");

            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',
            convertImagesToLinks: true,
            noModals: false,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            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%2f2858230%2fpme-journal-19-is-there-any-justification-for-solving-linear-linear-equation-w%23new-answer', 'question_page');

            );

            Post as a guest






























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            3
            down vote



            accepted










            They are (essentially) using a 'multiply and subtract' technique to simplify the equations.



            E.g. Multiply 1) by $d_2$ and 2) by $d_1$. Subtract and you get 4).



            You get 5) analogously with $d_3$ and $d_2$ on 2) and 3). Then, using the same idea, multiply 4) by $A_2$ and 5) by $A_1$, subtract and you get



            $$|A_1B_2|y + |A_1C_2|z = 0$$



            whence $fracyz = fracA_1B_2$ or $y:z = -|A_1C_2|:|A_1B_2|$.



            The same thing again gives the proportion for $x$. Once you have the proportions, you can substitute and solve for the values if necessary.






            share|cite|improve this answer

























              up vote
              3
              down vote



              accepted










              They are (essentially) using a 'multiply and subtract' technique to simplify the equations.



              E.g. Multiply 1) by $d_2$ and 2) by $d_1$. Subtract and you get 4).



              You get 5) analogously with $d_3$ and $d_2$ on 2) and 3). Then, using the same idea, multiply 4) by $A_2$ and 5) by $A_1$, subtract and you get



              $$|A_1B_2|y + |A_1C_2|z = 0$$



              whence $fracyz = fracA_1B_2$ or $y:z = -|A_1C_2|:|A_1B_2|$.



              The same thing again gives the proportion for $x$. Once you have the proportions, you can substitute and solve for the values if necessary.






              share|cite|improve this answer























                up vote
                3
                down vote



                accepted







                up vote
                3
                down vote



                accepted






                They are (essentially) using a 'multiply and subtract' technique to simplify the equations.



                E.g. Multiply 1) by $d_2$ and 2) by $d_1$. Subtract and you get 4).



                You get 5) analogously with $d_3$ and $d_2$ on 2) and 3). Then, using the same idea, multiply 4) by $A_2$ and 5) by $A_1$, subtract and you get



                $$|A_1B_2|y + |A_1C_2|z = 0$$



                whence $fracyz = fracA_1B_2$ or $y:z = -|A_1C_2|:|A_1B_2|$.



                The same thing again gives the proportion for $x$. Once you have the proportions, you can substitute and solve for the values if necessary.






                share|cite|improve this answer













                They are (essentially) using a 'multiply and subtract' technique to simplify the equations.



                E.g. Multiply 1) by $d_2$ and 2) by $d_1$. Subtract and you get 4).



                You get 5) analogously with $d_3$ and $d_2$ on 2) and 3). Then, using the same idea, multiply 4) by $A_2$ and 5) by $A_1$, subtract and you get



                $$|A_1B_2|y + |A_1C_2|z = 0$$



                whence $fracyz = fracA_1B_2$ or $y:z = -|A_1C_2|:|A_1B_2|$.



                The same thing again gives the proportion for $x$. Once you have the proportions, you can substitute and solve for the values if necessary.







                share|cite|improve this answer













                share|cite|improve this answer



                share|cite|improve this answer











                answered Jul 21 at 4:08









                Michael Biro

                10.7k21731




                10.7k21731






















                     

                    draft saved


                    draft discarded


























                     


                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function ()
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2858230%2fpme-journal-19-is-there-any-justification-for-solving-linear-linear-equation-w%23new-answer', 'question_page');

                    );

                    Post as a guest













































































                    Comments

                    Popular posts from this blog

                    What is the equation of a 3D cone with generalised tilt?

                    Color the edges and diagonals of a regular polygon

                    Relationship between determinant of matrix and determinant of adjoint?