Phenomena relating to the condition ($ab = cd$ or $a + b ne c + d$)











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Given numbers $a, b, c,; text{and}; d$ (not necessarily distinct), what phenomena is the condition $(ab = cd ; text{or} ; a + b neq c + d)$ linked to? I came across one, but I wanted to see if there were any others before revealing it.










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  • 2




    Please explain "I came accross one". Provide the proof here please.
    – Sujit Bhattacharyya
    Nov 20 at 15:17






  • 2




    What phenomenon did you come across?
    – Arthur
    Nov 20 at 15:19












  • Your condition is: $ $ equal sum $Rightarrow$ equal product, correct?
    – Bill Dubuque
    Nov 20 at 15:27












  • @BillDubuque: Yes, that would be an equivalent formulation.
    – EulerSpoiler
    Nov 20 at 16:33















up vote
-1
down vote

favorite












Given numbers $a, b, c,; text{and}; d$ (not necessarily distinct), what phenomena is the condition $(ab = cd ; text{or} ; a + b neq c + d)$ linked to? I came across one, but I wanted to see if there were any others before revealing it.










share|cite|improve this question




















  • 2




    Please explain "I came accross one". Provide the proof here please.
    – Sujit Bhattacharyya
    Nov 20 at 15:17






  • 2




    What phenomenon did you come across?
    – Arthur
    Nov 20 at 15:19












  • Your condition is: $ $ equal sum $Rightarrow$ equal product, correct?
    – Bill Dubuque
    Nov 20 at 15:27












  • @BillDubuque: Yes, that would be an equivalent formulation.
    – EulerSpoiler
    Nov 20 at 16:33













up vote
-1
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favorite









up vote
-1
down vote

favorite











Given numbers $a, b, c,; text{and}; d$ (not necessarily distinct), what phenomena is the condition $(ab = cd ; text{or} ; a + b neq c + d)$ linked to? I came across one, but I wanted to see if there were any others before revealing it.










share|cite|improve this question















Given numbers $a, b, c,; text{and}; d$ (not necessarily distinct), what phenomena is the condition $(ab = cd ; text{or} ; a + b neq c + d)$ linked to? I came across one, but I wanted to see if there were any others before revealing it.







algebra-precalculus






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edited Nov 20 at 23:11









user376343

2,6412819




2,6412819










asked Nov 20 at 15:10









EulerSpoiler

729




729








  • 2




    Please explain "I came accross one". Provide the proof here please.
    – Sujit Bhattacharyya
    Nov 20 at 15:17






  • 2




    What phenomenon did you come across?
    – Arthur
    Nov 20 at 15:19












  • Your condition is: $ $ equal sum $Rightarrow$ equal product, correct?
    – Bill Dubuque
    Nov 20 at 15:27












  • @BillDubuque: Yes, that would be an equivalent formulation.
    – EulerSpoiler
    Nov 20 at 16:33














  • 2




    Please explain "I came accross one". Provide the proof here please.
    – Sujit Bhattacharyya
    Nov 20 at 15:17






  • 2




    What phenomenon did you come across?
    – Arthur
    Nov 20 at 15:19












  • Your condition is: $ $ equal sum $Rightarrow$ equal product, correct?
    – Bill Dubuque
    Nov 20 at 15:27












  • @BillDubuque: Yes, that would be an equivalent formulation.
    – EulerSpoiler
    Nov 20 at 16:33








2




2




Please explain "I came accross one". Provide the proof here please.
– Sujit Bhattacharyya
Nov 20 at 15:17




Please explain "I came accross one". Provide the proof here please.
– Sujit Bhattacharyya
Nov 20 at 15:17




2




2




What phenomenon did you come across?
– Arthur
Nov 20 at 15:19






What phenomenon did you come across?
– Arthur
Nov 20 at 15:19














Your condition is: $ $ equal sum $Rightarrow$ equal product, correct?
– Bill Dubuque
Nov 20 at 15:27






Your condition is: $ $ equal sum $Rightarrow$ equal product, correct?
– Bill Dubuque
Nov 20 at 15:27














@BillDubuque: Yes, that would be an equivalent formulation.
– EulerSpoiler
Nov 20 at 16:33




@BillDubuque: Yes, that would be an equivalent formulation.
– EulerSpoiler
Nov 20 at 16:33










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Given constants a, b, c, and d, then the equation (x – a)(x – b) = (x – c)(x – d) has a nonempty solution set if, and only if, ab = cd or a + b != c + d.






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    Given constants a, b, c, and d, then the equation (x – a)(x – b) = (x – c)(x – d) has a nonempty solution set if, and only if, ab = cd or a + b != c + d.






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      Given constants a, b, c, and d, then the equation (x – a)(x – b) = (x – c)(x – d) has a nonempty solution set if, and only if, ab = cd or a + b != c + d.






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        up vote
        0
        down vote









        Given constants a, b, c, and d, then the equation (x – a)(x – b) = (x – c)(x – d) has a nonempty solution set if, and only if, ab = cd or a + b != c + d.






        share|cite|improve this answer












        Given constants a, b, c, and d, then the equation (x – a)(x – b) = (x – c)(x – d) has a nonempty solution set if, and only if, ab = cd or a + b != c + d.







        share|cite|improve this answer












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        share|cite|improve this answer










        answered Nov 22 at 3:48









        EulerSpoiler

        729




        729






























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