Solving for $x$ in a system of equations with 2 variables











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$$a^2-b^2-c^2=x^2-y^2quad &quad
ab=xy$$



Hi. So I have been trying to solve this equation (I'm looking for $x$, and $x$ and $y$ are the only variables) but I just can't find a solution. Please help. How do I find an expression for $x$?










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  • You can use the 2nd one to eliminate $y$ from the first to give a quadratic in $x^2$. there may be a neater way.
    – user121049
    Nov 18 at 13:01












  • But still, both sides will still have x. :(
    – Maria Mercedes
    Nov 18 at 14:52










  • You should end up with $x^4-(a^2-b^2-c^2)x^2-a^2b^2=0$.
    – user121049
    Nov 18 at 15:32

















up vote
0
down vote

favorite












$$a^2-b^2-c^2=x^2-y^2quad &quad
ab=xy$$



Hi. So I have been trying to solve this equation (I'm looking for $x$, and $x$ and $y$ are the only variables) but I just can't find a solution. Please help. How do I find an expression for $x$?










share|cite|improve this question
























  • You can use the 2nd one to eliminate $y$ from the first to give a quadratic in $x^2$. there may be a neater way.
    – user121049
    Nov 18 at 13:01












  • But still, both sides will still have x. :(
    – Maria Mercedes
    Nov 18 at 14:52










  • You should end up with $x^4-(a^2-b^2-c^2)x^2-a^2b^2=0$.
    – user121049
    Nov 18 at 15:32















up vote
0
down vote

favorite









up vote
0
down vote

favorite











$$a^2-b^2-c^2=x^2-y^2quad &quad
ab=xy$$



Hi. So I have been trying to solve this equation (I'm looking for $x$, and $x$ and $y$ are the only variables) but I just can't find a solution. Please help. How do I find an expression for $x$?










share|cite|improve this question















$$a^2-b^2-c^2=x^2-y^2quad &quad
ab=xy$$



Hi. So I have been trying to solve this equation (I'm looking for $x$, and $x$ and $y$ are the only variables) but I just can't find a solution. Please help. How do I find an expression for $x$?







algebra-precalculus






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edited Nov 18 at 13:21









amWhy

191k27223439




191k27223439










asked Nov 18 at 12:55









Maria Mercedes

1




1












  • You can use the 2nd one to eliminate $y$ from the first to give a quadratic in $x^2$. there may be a neater way.
    – user121049
    Nov 18 at 13:01












  • But still, both sides will still have x. :(
    – Maria Mercedes
    Nov 18 at 14:52










  • You should end up with $x^4-(a^2-b^2-c^2)x^2-a^2b^2=0$.
    – user121049
    Nov 18 at 15:32




















  • You can use the 2nd one to eliminate $y$ from the first to give a quadratic in $x^2$. there may be a neater way.
    – user121049
    Nov 18 at 13:01












  • But still, both sides will still have x. :(
    – Maria Mercedes
    Nov 18 at 14:52










  • You should end up with $x^4-(a^2-b^2-c^2)x^2-a^2b^2=0$.
    – user121049
    Nov 18 at 15:32


















You can use the 2nd one to eliminate $y$ from the first to give a quadratic in $x^2$. there may be a neater way.
– user121049
Nov 18 at 13:01






You can use the 2nd one to eliminate $y$ from the first to give a quadratic in $x^2$. there may be a neater way.
– user121049
Nov 18 at 13:01














But still, both sides will still have x. :(
– Maria Mercedes
Nov 18 at 14:52




But still, both sides will still have x. :(
– Maria Mercedes
Nov 18 at 14:52












You should end up with $x^4-(a^2-b^2-c^2)x^2-a^2b^2=0$.
– user121049
Nov 18 at 15:32






You should end up with $x^4-(a^2-b^2-c^2)x^2-a^2b^2=0$.
– user121049
Nov 18 at 15:32












1 Answer
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Multiply all terms by $x^2$
$x^2(a^2-b^2-c^2)= x^4-(xy)^2$ then it turns out to be
$(x^2)^2-x^2(a^2-b^2-c^2) -(ab)^2=0$
Use quadratic formula






share|cite|improve this answer





















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    down vote













    Multiply all terms by $x^2$
    $x^2(a^2-b^2-c^2)= x^4-(xy)^2$ then it turns out to be
    $(x^2)^2-x^2(a^2-b^2-c^2) -(ab)^2=0$
    Use quadratic formula






    share|cite|improve this answer

























      up vote
      0
      down vote













      Multiply all terms by $x^2$
      $x^2(a^2-b^2-c^2)= x^4-(xy)^2$ then it turns out to be
      $(x^2)^2-x^2(a^2-b^2-c^2) -(ab)^2=0$
      Use quadratic formula






      share|cite|improve this answer























        up vote
        0
        down vote










        up vote
        0
        down vote









        Multiply all terms by $x^2$
        $x^2(a^2-b^2-c^2)= x^4-(xy)^2$ then it turns out to be
        $(x^2)^2-x^2(a^2-b^2-c^2) -(ab)^2=0$
        Use quadratic formula






        share|cite|improve this answer












        Multiply all terms by $x^2$
        $x^2(a^2-b^2-c^2)= x^4-(xy)^2$ then it turns out to be
        $(x^2)^2-x^2(a^2-b^2-c^2) -(ab)^2=0$
        Use quadratic formula







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 18 at 23:30









        Ameryr

        599211




        599211






























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