How do you solve these 2 equations?












0














$$xy = 1/6$$
$$y+x = 5xy$$
I tried solving them using all methods - substitution, elimination and graphing - but can't get the solutions










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  • What were "all those methods" that you tried?
    – Parcly Taxel
    Nov 18 '18 at 6:07










  • Substitution, elimination and graphing.
    – Jullian Santos
    Nov 18 '18 at 6:11










  • Take the first equation and insert it into the second
    – Fakemistake
    Nov 18 '18 at 6:11










  • Actually I can't use the graphing so what I meant was substitution and elimination.
    – Jullian Santos
    Nov 18 '18 at 6:12










  • Remember if the amount of variables and amount of equations are equal, you can always solve that system of equations. Just substitute the value of any one variable from one equation in another.
    – PradyumanDixit
    Nov 18 '18 at 6:12
















0














$$xy = 1/6$$
$$y+x = 5xy$$
I tried solving them using all methods - substitution, elimination and graphing - but can't get the solutions










share|cite|improve this question
























  • What were "all those methods" that you tried?
    – Parcly Taxel
    Nov 18 '18 at 6:07










  • Substitution, elimination and graphing.
    – Jullian Santos
    Nov 18 '18 at 6:11










  • Take the first equation and insert it into the second
    – Fakemistake
    Nov 18 '18 at 6:11










  • Actually I can't use the graphing so what I meant was substitution and elimination.
    – Jullian Santos
    Nov 18 '18 at 6:12










  • Remember if the amount of variables and amount of equations are equal, you can always solve that system of equations. Just substitute the value of any one variable from one equation in another.
    – PradyumanDixit
    Nov 18 '18 at 6:12














0












0








0







$$xy = 1/6$$
$$y+x = 5xy$$
I tried solving them using all methods - substitution, elimination and graphing - but can't get the solutions










share|cite|improve this question















$$xy = 1/6$$
$$y+x = 5xy$$
I tried solving them using all methods - substitution, elimination and graphing - but can't get the solutions







systems-of-equations quadratics symmetric-polynomials






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share|cite|improve this question













share|cite|improve this question




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edited Nov 23 '18 at 11:59









Harry Peter

5,46111439




5,46111439










asked Nov 18 '18 at 6:06









Jullian SantosJullian Santos

6




6












  • What were "all those methods" that you tried?
    – Parcly Taxel
    Nov 18 '18 at 6:07










  • Substitution, elimination and graphing.
    – Jullian Santos
    Nov 18 '18 at 6:11










  • Take the first equation and insert it into the second
    – Fakemistake
    Nov 18 '18 at 6:11










  • Actually I can't use the graphing so what I meant was substitution and elimination.
    – Jullian Santos
    Nov 18 '18 at 6:12










  • Remember if the amount of variables and amount of equations are equal, you can always solve that system of equations. Just substitute the value of any one variable from one equation in another.
    – PradyumanDixit
    Nov 18 '18 at 6:12


















  • What were "all those methods" that you tried?
    – Parcly Taxel
    Nov 18 '18 at 6:07










  • Substitution, elimination and graphing.
    – Jullian Santos
    Nov 18 '18 at 6:11










  • Take the first equation and insert it into the second
    – Fakemistake
    Nov 18 '18 at 6:11










  • Actually I can't use the graphing so what I meant was substitution and elimination.
    – Jullian Santos
    Nov 18 '18 at 6:12










  • Remember if the amount of variables and amount of equations are equal, you can always solve that system of equations. Just substitute the value of any one variable from one equation in another.
    – PradyumanDixit
    Nov 18 '18 at 6:12
















What were "all those methods" that you tried?
– Parcly Taxel
Nov 18 '18 at 6:07




What were "all those methods" that you tried?
– Parcly Taxel
Nov 18 '18 at 6:07












Substitution, elimination and graphing.
– Jullian Santos
Nov 18 '18 at 6:11




Substitution, elimination and graphing.
– Jullian Santos
Nov 18 '18 at 6:11












Take the first equation and insert it into the second
– Fakemistake
Nov 18 '18 at 6:11




Take the first equation and insert it into the second
– Fakemistake
Nov 18 '18 at 6:11












Actually I can't use the graphing so what I meant was substitution and elimination.
– Jullian Santos
Nov 18 '18 at 6:12




Actually I can't use the graphing so what I meant was substitution and elimination.
– Jullian Santos
Nov 18 '18 at 6:12












Remember if the amount of variables and amount of equations are equal, you can always solve that system of equations. Just substitute the value of any one variable from one equation in another.
– PradyumanDixit
Nov 18 '18 at 6:12




Remember if the amount of variables and amount of equations are equal, you can always solve that system of equations. Just substitute the value of any one variable from one equation in another.
– PradyumanDixit
Nov 18 '18 at 6:12










3 Answers
3






active

oldest

votes


















2














You can solve this equation by using substitution of variables.



Using the first equation $xy=1/6$, we can rewrite it as $y=frac1{6x}$.



Plugging this in to the second equation, we get $$x+frac1{6x}=5frac{x}{6x}$$



Simplify the right-hand side to $frac56$ and multiply both sides by $x$ to obtain



$$x^2+frac16=frac56x to x^2-frac56x+frac16=0$$



Using the quadratic formula, we now have $$x=frac{frac56 pm sqrt{frac{25}{36}-frac46}}{2}=frac5{12} pm frac12sqrt{frac1{36}}=frac5{12} pm frac1{12}$$



Our solutions for $x$ are $frac13$ and $frac12$. Using $y=frac1{6x}$, we get the coordinate pairs to be $(frac13,frac12)$ and $(frac12,frac13)$.






share|cite|improve this answer

















  • 2




    In the quadratic equation, it's easier to compute if we just first multiply both sides with $6$ to get $6x^2 -5x +1=0$, and get only integers to compute with. The determinant becomes $(-5)^2 - 4cdot 6 = 1$ so we get a nice result.
    – Henno Brandsma
    Nov 18 '18 at 6:27










  • Thanks for the answer!
    – Jullian Santos
    Nov 18 '18 at 6:27



















0














1) Substitute $;xy=frac{1}{6}$ into the 2nd equation to get $;x+y=frac{5}{6}$



2) Solving $;xy=frac{1}{6}$ and $;x+y=frac{5}{6};$ is equivalent to finding the zeros of the function $f(z)=z^2+frac{5}{6}z+frac{1}{6}=0,;$ so using the quadratic formula, $;x=-frac{1}{3};text{and}; y=-frac{1}{2};$ or $;y=-frac{1}{3};text{and};x=-frac{1}{2}.$






share|cite|improve this answer























  • Would you check your quadratic equation? The signs.
    – user376343
    Dec 29 '18 at 10:00



















0














begin{array}{c}
xy = frac 16 \
x + y = 5xy = frac 56
end{array}



Let $x = frac{5}{12} + t$ and $y = frac{5}{12}-t$. Then $x+y=frac 56$.



begin{align}
xy &= frac 16 \
bigg(frac{5}{12} + t bigg) bigg(frac{5}{12} - tbigg) &= frac 16 \
frac{25}{144} - t^2 &= frac{24}{144} \
t^2 &= frac{1}{144} \
t &= pm frac{1}{12} \
end{align}



$frac{5}{12} + frac{1}{12} = frac 12$ and $frac{5}{12} - frac{1}{12} = frac 13$



So $(x,y) = left{big(frac 12,frac 13 big),big(frac 13,frac 12 big)right}$






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    3 Answers
    3






    active

    oldest

    votes








    3 Answers
    3






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    2














    You can solve this equation by using substitution of variables.



    Using the first equation $xy=1/6$, we can rewrite it as $y=frac1{6x}$.



    Plugging this in to the second equation, we get $$x+frac1{6x}=5frac{x}{6x}$$



    Simplify the right-hand side to $frac56$ and multiply both sides by $x$ to obtain



    $$x^2+frac16=frac56x to x^2-frac56x+frac16=0$$



    Using the quadratic formula, we now have $$x=frac{frac56 pm sqrt{frac{25}{36}-frac46}}{2}=frac5{12} pm frac12sqrt{frac1{36}}=frac5{12} pm frac1{12}$$



    Our solutions for $x$ are $frac13$ and $frac12$. Using $y=frac1{6x}$, we get the coordinate pairs to be $(frac13,frac12)$ and $(frac12,frac13)$.






    share|cite|improve this answer

















    • 2




      In the quadratic equation, it's easier to compute if we just first multiply both sides with $6$ to get $6x^2 -5x +1=0$, and get only integers to compute with. The determinant becomes $(-5)^2 - 4cdot 6 = 1$ so we get a nice result.
      – Henno Brandsma
      Nov 18 '18 at 6:27










    • Thanks for the answer!
      – Jullian Santos
      Nov 18 '18 at 6:27
















    2














    You can solve this equation by using substitution of variables.



    Using the first equation $xy=1/6$, we can rewrite it as $y=frac1{6x}$.



    Plugging this in to the second equation, we get $$x+frac1{6x}=5frac{x}{6x}$$



    Simplify the right-hand side to $frac56$ and multiply both sides by $x$ to obtain



    $$x^2+frac16=frac56x to x^2-frac56x+frac16=0$$



    Using the quadratic formula, we now have $$x=frac{frac56 pm sqrt{frac{25}{36}-frac46}}{2}=frac5{12} pm frac12sqrt{frac1{36}}=frac5{12} pm frac1{12}$$



    Our solutions for $x$ are $frac13$ and $frac12$. Using $y=frac1{6x}$, we get the coordinate pairs to be $(frac13,frac12)$ and $(frac12,frac13)$.






    share|cite|improve this answer

















    • 2




      In the quadratic equation, it's easier to compute if we just first multiply both sides with $6$ to get $6x^2 -5x +1=0$, and get only integers to compute with. The determinant becomes $(-5)^2 - 4cdot 6 = 1$ so we get a nice result.
      – Henno Brandsma
      Nov 18 '18 at 6:27










    • Thanks for the answer!
      – Jullian Santos
      Nov 18 '18 at 6:27














    2












    2








    2






    You can solve this equation by using substitution of variables.



    Using the first equation $xy=1/6$, we can rewrite it as $y=frac1{6x}$.



    Plugging this in to the second equation, we get $$x+frac1{6x}=5frac{x}{6x}$$



    Simplify the right-hand side to $frac56$ and multiply both sides by $x$ to obtain



    $$x^2+frac16=frac56x to x^2-frac56x+frac16=0$$



    Using the quadratic formula, we now have $$x=frac{frac56 pm sqrt{frac{25}{36}-frac46}}{2}=frac5{12} pm frac12sqrt{frac1{36}}=frac5{12} pm frac1{12}$$



    Our solutions for $x$ are $frac13$ and $frac12$. Using $y=frac1{6x}$, we get the coordinate pairs to be $(frac13,frac12)$ and $(frac12,frac13)$.






    share|cite|improve this answer












    You can solve this equation by using substitution of variables.



    Using the first equation $xy=1/6$, we can rewrite it as $y=frac1{6x}$.



    Plugging this in to the second equation, we get $$x+frac1{6x}=5frac{x}{6x}$$



    Simplify the right-hand side to $frac56$ and multiply both sides by $x$ to obtain



    $$x^2+frac16=frac56x to x^2-frac56x+frac16=0$$



    Using the quadratic formula, we now have $$x=frac{frac56 pm sqrt{frac{25}{36}-frac46}}{2}=frac5{12} pm frac12sqrt{frac1{36}}=frac5{12} pm frac1{12}$$



    Our solutions for $x$ are $frac13$ and $frac12$. Using $y=frac1{6x}$, we get the coordinate pairs to be $(frac13,frac12)$ and $(frac12,frac13)$.







    share|cite|improve this answer












    share|cite|improve this answer



    share|cite|improve this answer










    answered Nov 18 '18 at 6:20









    Christopher MarleyChristopher Marley

    1,020115




    1,020115








    • 2




      In the quadratic equation, it's easier to compute if we just first multiply both sides with $6$ to get $6x^2 -5x +1=0$, and get only integers to compute with. The determinant becomes $(-5)^2 - 4cdot 6 = 1$ so we get a nice result.
      – Henno Brandsma
      Nov 18 '18 at 6:27










    • Thanks for the answer!
      – Jullian Santos
      Nov 18 '18 at 6:27














    • 2




      In the quadratic equation, it's easier to compute if we just first multiply both sides with $6$ to get $6x^2 -5x +1=0$, and get only integers to compute with. The determinant becomes $(-5)^2 - 4cdot 6 = 1$ so we get a nice result.
      – Henno Brandsma
      Nov 18 '18 at 6:27










    • Thanks for the answer!
      – Jullian Santos
      Nov 18 '18 at 6:27








    2




    2




    In the quadratic equation, it's easier to compute if we just first multiply both sides with $6$ to get $6x^2 -5x +1=0$, and get only integers to compute with. The determinant becomes $(-5)^2 - 4cdot 6 = 1$ so we get a nice result.
    – Henno Brandsma
    Nov 18 '18 at 6:27




    In the quadratic equation, it's easier to compute if we just first multiply both sides with $6$ to get $6x^2 -5x +1=0$, and get only integers to compute with. The determinant becomes $(-5)^2 - 4cdot 6 = 1$ so we get a nice result.
    – Henno Brandsma
    Nov 18 '18 at 6:27












    Thanks for the answer!
    – Jullian Santos
    Nov 18 '18 at 6:27




    Thanks for the answer!
    – Jullian Santos
    Nov 18 '18 at 6:27











    0














    1) Substitute $;xy=frac{1}{6}$ into the 2nd equation to get $;x+y=frac{5}{6}$



    2) Solving $;xy=frac{1}{6}$ and $;x+y=frac{5}{6};$ is equivalent to finding the zeros of the function $f(z)=z^2+frac{5}{6}z+frac{1}{6}=0,;$ so using the quadratic formula, $;x=-frac{1}{3};text{and}; y=-frac{1}{2};$ or $;y=-frac{1}{3};text{and};x=-frac{1}{2}.$






    share|cite|improve this answer























    • Would you check your quadratic equation? The signs.
      – user376343
      Dec 29 '18 at 10:00
















    0














    1) Substitute $;xy=frac{1}{6}$ into the 2nd equation to get $;x+y=frac{5}{6}$



    2) Solving $;xy=frac{1}{6}$ and $;x+y=frac{5}{6};$ is equivalent to finding the zeros of the function $f(z)=z^2+frac{5}{6}z+frac{1}{6}=0,;$ so using the quadratic formula, $;x=-frac{1}{3};text{and}; y=-frac{1}{2};$ or $;y=-frac{1}{3};text{and};x=-frac{1}{2}.$






    share|cite|improve this answer























    • Would you check your quadratic equation? The signs.
      – user376343
      Dec 29 '18 at 10:00














    0












    0








    0






    1) Substitute $;xy=frac{1}{6}$ into the 2nd equation to get $;x+y=frac{5}{6}$



    2) Solving $;xy=frac{1}{6}$ and $;x+y=frac{5}{6};$ is equivalent to finding the zeros of the function $f(z)=z^2+frac{5}{6}z+frac{1}{6}=0,;$ so using the quadratic formula, $;x=-frac{1}{3};text{and}; y=-frac{1}{2};$ or $;y=-frac{1}{3};text{and};x=-frac{1}{2}.$






    share|cite|improve this answer














    1) Substitute $;xy=frac{1}{6}$ into the 2nd equation to get $;x+y=frac{5}{6}$



    2) Solving $;xy=frac{1}{6}$ and $;x+y=frac{5}{6};$ is equivalent to finding the zeros of the function $f(z)=z^2+frac{5}{6}z+frac{1}{6}=0,;$ so using the quadratic formula, $;x=-frac{1}{3};text{and}; y=-frac{1}{2};$ or $;y=-frac{1}{3};text{and};x=-frac{1}{2}.$







    share|cite|improve this answer














    share|cite|improve this answer



    share|cite|improve this answer








    edited Dec 29 '18 at 9:58









    user376343

    3,0032823




    3,0032823










    answered Nov 18 '18 at 6:23









    Muchang BahngMuchang Bahng

    663




    663












    • Would you check your quadratic equation? The signs.
      – user376343
      Dec 29 '18 at 10:00


















    • Would you check your quadratic equation? The signs.
      – user376343
      Dec 29 '18 at 10:00
















    Would you check your quadratic equation? The signs.
    – user376343
    Dec 29 '18 at 10:00




    Would you check your quadratic equation? The signs.
    – user376343
    Dec 29 '18 at 10:00











    0














    begin{array}{c}
    xy = frac 16 \
    x + y = 5xy = frac 56
    end{array}



    Let $x = frac{5}{12} + t$ and $y = frac{5}{12}-t$. Then $x+y=frac 56$.



    begin{align}
    xy &= frac 16 \
    bigg(frac{5}{12} + t bigg) bigg(frac{5}{12} - tbigg) &= frac 16 \
    frac{25}{144} - t^2 &= frac{24}{144} \
    t^2 &= frac{1}{144} \
    t &= pm frac{1}{12} \
    end{align}



    $frac{5}{12} + frac{1}{12} = frac 12$ and $frac{5}{12} - frac{1}{12} = frac 13$



    So $(x,y) = left{big(frac 12,frac 13 big),big(frac 13,frac 12 big)right}$






    share|cite|improve this answer




























      0














      begin{array}{c}
      xy = frac 16 \
      x + y = 5xy = frac 56
      end{array}



      Let $x = frac{5}{12} + t$ and $y = frac{5}{12}-t$. Then $x+y=frac 56$.



      begin{align}
      xy &= frac 16 \
      bigg(frac{5}{12} + t bigg) bigg(frac{5}{12} - tbigg) &= frac 16 \
      frac{25}{144} - t^2 &= frac{24}{144} \
      t^2 &= frac{1}{144} \
      t &= pm frac{1}{12} \
      end{align}



      $frac{5}{12} + frac{1}{12} = frac 12$ and $frac{5}{12} - frac{1}{12} = frac 13$



      So $(x,y) = left{big(frac 12,frac 13 big),big(frac 13,frac 12 big)right}$






      share|cite|improve this answer


























        0












        0








        0






        begin{array}{c}
        xy = frac 16 \
        x + y = 5xy = frac 56
        end{array}



        Let $x = frac{5}{12} + t$ and $y = frac{5}{12}-t$. Then $x+y=frac 56$.



        begin{align}
        xy &= frac 16 \
        bigg(frac{5}{12} + t bigg) bigg(frac{5}{12} - tbigg) &= frac 16 \
        frac{25}{144} - t^2 &= frac{24}{144} \
        t^2 &= frac{1}{144} \
        t &= pm frac{1}{12} \
        end{align}



        $frac{5}{12} + frac{1}{12} = frac 12$ and $frac{5}{12} - frac{1}{12} = frac 13$



        So $(x,y) = left{big(frac 12,frac 13 big),big(frac 13,frac 12 big)right}$






        share|cite|improve this answer














        begin{array}{c}
        xy = frac 16 \
        x + y = 5xy = frac 56
        end{array}



        Let $x = frac{5}{12} + t$ and $y = frac{5}{12}-t$. Then $x+y=frac 56$.



        begin{align}
        xy &= frac 16 \
        bigg(frac{5}{12} + t bigg) bigg(frac{5}{12} - tbigg) &= frac 16 \
        frac{25}{144} - t^2 &= frac{24}{144} \
        t^2 &= frac{1}{144} \
        t &= pm frac{1}{12} \
        end{align}



        $frac{5}{12} + frac{1}{12} = frac 12$ and $frac{5}{12} - frac{1}{12} = frac 13$



        So $(x,y) = left{big(frac 12,frac 13 big),big(frac 13,frac 12 big)right}$







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Dec 30 '18 at 21:32

























        answered Dec 29 '18 at 10:36









        steven gregorysteven gregory

        17.7k32257




        17.7k32257






























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