How can I factorize this: “$X^3 + X^2 + X - 3$”

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1
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I am going to elementary school & I am living in one of those deprived areas of Africa.



I can solve mathematical questions like this:



$$X^3 + X^2 + X +1 = X^2(X+1)+(X+1) = (X+1)(X^2+1)$$



Or even



beginalignX^2 − 2X + X^2 - X + 1 &= (X^2 - 2X + 1) + (X^2 - X) \
&= (X - 1)^2 + X(X - 1) \
&= (X-1)(X-1+X) \
&= (X - 1)(2X - 1)
endalign



But for a few months I have not been able to find a teacher around here who can factorize this:



$$X^3 + X^2 + X - 3$$



Do we have to solve it in this way?



$$X^3 + X^2 + X - 3 = X^2(X + 1) + X - 3$$



Or something else?
I'd appreciate your help with this.







share|cite|improve this question






















  • Hint: $x=1$ is a root of your polynomial, meaning that the polynomial is divisible by $x-1$.
    – Sobi
    Aug 22 at 8:13







  • 1




    $X^3+X^2+X-3 = X^3-1 + X^2-1 + X-1 = (X-1)(X^2+X+1)+(X-1)(X+1)+(X-1) = (X-1)(X^2+2X+3)$, $X^2+2X+3$ you can't factorize when working with real numbers
    – Rumpelstiltskin
    Aug 22 at 8:15











  • @AmirhoseinRiazi You might want to look at this or this
    – Rumpelstiltskin
    Aug 22 at 8:29











  • Please use MathJax to format your posts.
    – Chase Ryan Taylor
    Aug 22 at 9:19










  • @ChaseRyanTaylor Excuse me, this question may seem strange or silly, but I do not know how to use this MathJox. I'm new to this, where should I start from?
    – AmirhoseinRiazi
    Aug 22 at 11:14















up vote
1
down vote

favorite












I am going to elementary school & I am living in one of those deprived areas of Africa.



I can solve mathematical questions like this:



$$X^3 + X^2 + X +1 = X^2(X+1)+(X+1) = (X+1)(X^2+1)$$



Or even



beginalignX^2 − 2X + X^2 - X + 1 &= (X^2 - 2X + 1) + (X^2 - X) \
&= (X - 1)^2 + X(X - 1) \
&= (X-1)(X-1+X) \
&= (X - 1)(2X - 1)
endalign



But for a few months I have not been able to find a teacher around here who can factorize this:



$$X^3 + X^2 + X - 3$$



Do we have to solve it in this way?



$$X^3 + X^2 + X - 3 = X^2(X + 1) + X - 3$$



Or something else?
I'd appreciate your help with this.







share|cite|improve this question






















  • Hint: $x=1$ is a root of your polynomial, meaning that the polynomial is divisible by $x-1$.
    – Sobi
    Aug 22 at 8:13







  • 1




    $X^3+X^2+X-3 = X^3-1 + X^2-1 + X-1 = (X-1)(X^2+X+1)+(X-1)(X+1)+(X-1) = (X-1)(X^2+2X+3)$, $X^2+2X+3$ you can't factorize when working with real numbers
    – Rumpelstiltskin
    Aug 22 at 8:15











  • @AmirhoseinRiazi You might want to look at this or this
    – Rumpelstiltskin
    Aug 22 at 8:29











  • Please use MathJax to format your posts.
    – Chase Ryan Taylor
    Aug 22 at 9:19










  • @ChaseRyanTaylor Excuse me, this question may seem strange or silly, but I do not know how to use this MathJox. I'm new to this, where should I start from?
    – AmirhoseinRiazi
    Aug 22 at 11:14













up vote
1
down vote

favorite









up vote
1
down vote

favorite











I am going to elementary school & I am living in one of those deprived areas of Africa.



I can solve mathematical questions like this:



$$X^3 + X^2 + X +1 = X^2(X+1)+(X+1) = (X+1)(X^2+1)$$



Or even



beginalignX^2 − 2X + X^2 - X + 1 &= (X^2 - 2X + 1) + (X^2 - X) \
&= (X - 1)^2 + X(X - 1) \
&= (X-1)(X-1+X) \
&= (X - 1)(2X - 1)
endalign



But for a few months I have not been able to find a teacher around here who can factorize this:



$$X^3 + X^2 + X - 3$$



Do we have to solve it in this way?



$$X^3 + X^2 + X - 3 = X^2(X + 1) + X - 3$$



Or something else?
I'd appreciate your help with this.







share|cite|improve this question














I am going to elementary school & I am living in one of those deprived areas of Africa.



I can solve mathematical questions like this:



$$X^3 + X^2 + X +1 = X^2(X+1)+(X+1) = (X+1)(X^2+1)$$



Or even



beginalignX^2 − 2X + X^2 - X + 1 &= (X^2 - 2X + 1) + (X^2 - X) \
&= (X - 1)^2 + X(X - 1) \
&= (X-1)(X-1+X) \
&= (X - 1)(2X - 1)
endalign



But for a few months I have not been able to find a teacher around here who can factorize this:



$$X^3 + X^2 + X - 3$$



Do we have to solve it in this way?



$$X^3 + X^2 + X - 3 = X^2(X + 1) + X - 3$$



Or something else?
I'd appreciate your help with this.









share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Aug 22 at 10:54









Daniel Buck

2,5151625




2,5151625










asked Aug 22 at 8:12









AmirhoseinRiazi

1114




1114











  • Hint: $x=1$ is a root of your polynomial, meaning that the polynomial is divisible by $x-1$.
    – Sobi
    Aug 22 at 8:13







  • 1




    $X^3+X^2+X-3 = X^3-1 + X^2-1 + X-1 = (X-1)(X^2+X+1)+(X-1)(X+1)+(X-1) = (X-1)(X^2+2X+3)$, $X^2+2X+3$ you can't factorize when working with real numbers
    – Rumpelstiltskin
    Aug 22 at 8:15











  • @AmirhoseinRiazi You might want to look at this or this
    – Rumpelstiltskin
    Aug 22 at 8:29











  • Please use MathJax to format your posts.
    – Chase Ryan Taylor
    Aug 22 at 9:19










  • @ChaseRyanTaylor Excuse me, this question may seem strange or silly, but I do not know how to use this MathJox. I'm new to this, where should I start from?
    – AmirhoseinRiazi
    Aug 22 at 11:14

















  • Hint: $x=1$ is a root of your polynomial, meaning that the polynomial is divisible by $x-1$.
    – Sobi
    Aug 22 at 8:13







  • 1




    $X^3+X^2+X-3 = X^3-1 + X^2-1 + X-1 = (X-1)(X^2+X+1)+(X-1)(X+1)+(X-1) = (X-1)(X^2+2X+3)$, $X^2+2X+3$ you can't factorize when working with real numbers
    – Rumpelstiltskin
    Aug 22 at 8:15











  • @AmirhoseinRiazi You might want to look at this or this
    – Rumpelstiltskin
    Aug 22 at 8:29











  • Please use MathJax to format your posts.
    – Chase Ryan Taylor
    Aug 22 at 9:19










  • @ChaseRyanTaylor Excuse me, this question may seem strange or silly, but I do not know how to use this MathJox. I'm new to this, where should I start from?
    – AmirhoseinRiazi
    Aug 22 at 11:14
















Hint: $x=1$ is a root of your polynomial, meaning that the polynomial is divisible by $x-1$.
– Sobi
Aug 22 at 8:13





Hint: $x=1$ is a root of your polynomial, meaning that the polynomial is divisible by $x-1$.
– Sobi
Aug 22 at 8:13





1




1




$X^3+X^2+X-3 = X^3-1 + X^2-1 + X-1 = (X-1)(X^2+X+1)+(X-1)(X+1)+(X-1) = (X-1)(X^2+2X+3)$, $X^2+2X+3$ you can't factorize when working with real numbers
– Rumpelstiltskin
Aug 22 at 8:15





$X^3+X^2+X-3 = X^3-1 + X^2-1 + X-1 = (X-1)(X^2+X+1)+(X-1)(X+1)+(X-1) = (X-1)(X^2+2X+3)$, $X^2+2X+3$ you can't factorize when working with real numbers
– Rumpelstiltskin
Aug 22 at 8:15













@AmirhoseinRiazi You might want to look at this or this
– Rumpelstiltskin
Aug 22 at 8:29





@AmirhoseinRiazi You might want to look at this or this
– Rumpelstiltskin
Aug 22 at 8:29













Please use MathJax to format your posts.
– Chase Ryan Taylor
Aug 22 at 9:19




Please use MathJax to format your posts.
– Chase Ryan Taylor
Aug 22 at 9:19












@ChaseRyanTaylor Excuse me, this question may seem strange or silly, but I do not know how to use this MathJox. I'm new to this, where should I start from?
– AmirhoseinRiazi
Aug 22 at 11:14





@ChaseRyanTaylor Excuse me, this question may seem strange or silly, but I do not know how to use this MathJox. I'm new to this, where should I start from?
– AmirhoseinRiazi
Aug 22 at 11:14











3 Answers
3






active

oldest

votes

















up vote
4
down vote













Surely $1$ is a root of $x^3+x^2+x-3$ therefore $x-1$ is a factor of it. We have $$x^3+x^2+x-3=(x-1)(x^2+x+1+x+1+1)=(x-1)(x^2+2x+3)$$






share|cite|improve this answer




















  • I will show this to my teacher, he maybe recall, thanks a lot!
    – AmirhoseinRiazi
    Aug 22 at 8:27







  • 1




    You're welcome! Good luck!
    – Mostafa Ayaz
    Aug 22 at 8:31

















up vote
3
down vote













Hint: $(x^3+x^2+x-3):(x-1)=x^2+2x+3$






share|cite|improve this answer



























    up vote
    3
    down vote













    For this kind of problem it is worth knowing about the factor theorem



    This says if $a$ is a root of your polynomial $f(x)$ i.e. $f(a)=0$ then $x-a$ is a factor of, i.e. divides, the polynomial.



    In these kinds of problems it is worth trying a few values such as $pm1, pm2$.



    In your example $f(1)=0$ so $x-1$ divides your polynomial, allowing you to factorize it as $(x-1)(Ax^2+Bx+C)$ where you need to find $A,B,C$.






    share|cite|improve this answer






















    • Useful, I can't adequately express my gratefulness!
      – AmirhoseinRiazi
      Aug 22 at 9:21










    • Thank-you. I am very pleased it helped you.
      – PM.
      Aug 22 at 9:25










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    3 Answers
    3






    active

    oldest

    votes








    3 Answers
    3






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    4
    down vote













    Surely $1$ is a root of $x^3+x^2+x-3$ therefore $x-1$ is a factor of it. We have $$x^3+x^2+x-3=(x-1)(x^2+x+1+x+1+1)=(x-1)(x^2+2x+3)$$






    share|cite|improve this answer




















    • I will show this to my teacher, he maybe recall, thanks a lot!
      – AmirhoseinRiazi
      Aug 22 at 8:27







    • 1




      You're welcome! Good luck!
      – Mostafa Ayaz
      Aug 22 at 8:31














    up vote
    4
    down vote













    Surely $1$ is a root of $x^3+x^2+x-3$ therefore $x-1$ is a factor of it. We have $$x^3+x^2+x-3=(x-1)(x^2+x+1+x+1+1)=(x-1)(x^2+2x+3)$$






    share|cite|improve this answer




















    • I will show this to my teacher, he maybe recall, thanks a lot!
      – AmirhoseinRiazi
      Aug 22 at 8:27







    • 1




      You're welcome! Good luck!
      – Mostafa Ayaz
      Aug 22 at 8:31












    up vote
    4
    down vote










    up vote
    4
    down vote









    Surely $1$ is a root of $x^3+x^2+x-3$ therefore $x-1$ is a factor of it. We have $$x^3+x^2+x-3=(x-1)(x^2+x+1+x+1+1)=(x-1)(x^2+2x+3)$$






    share|cite|improve this answer












    Surely $1$ is a root of $x^3+x^2+x-3$ therefore $x-1$ is a factor of it. We have $$x^3+x^2+x-3=(x-1)(x^2+x+1+x+1+1)=(x-1)(x^2+2x+3)$$







    share|cite|improve this answer












    share|cite|improve this answer



    share|cite|improve this answer










    answered Aug 22 at 8:15









    Mostafa Ayaz

    10.1k3730




    10.1k3730











    • I will show this to my teacher, he maybe recall, thanks a lot!
      – AmirhoseinRiazi
      Aug 22 at 8:27







    • 1




      You're welcome! Good luck!
      – Mostafa Ayaz
      Aug 22 at 8:31
















    • I will show this to my teacher, he maybe recall, thanks a lot!
      – AmirhoseinRiazi
      Aug 22 at 8:27







    • 1




      You're welcome! Good luck!
      – Mostafa Ayaz
      Aug 22 at 8:31















    I will show this to my teacher, he maybe recall, thanks a lot!
    – AmirhoseinRiazi
    Aug 22 at 8:27





    I will show this to my teacher, he maybe recall, thanks a lot!
    – AmirhoseinRiazi
    Aug 22 at 8:27





    1




    1




    You're welcome! Good luck!
    – Mostafa Ayaz
    Aug 22 at 8:31




    You're welcome! Good luck!
    – Mostafa Ayaz
    Aug 22 at 8:31










    up vote
    3
    down vote













    Hint: $(x^3+x^2+x-3):(x-1)=x^2+2x+3$






    share|cite|improve this answer
























      up vote
      3
      down vote













      Hint: $(x^3+x^2+x-3):(x-1)=x^2+2x+3$






      share|cite|improve this answer






















        up vote
        3
        down vote










        up vote
        3
        down vote









        Hint: $(x^3+x^2+x-3):(x-1)=x^2+2x+3$






        share|cite|improve this answer












        Hint: $(x^3+x^2+x-3):(x-1)=x^2+2x+3$







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Aug 22 at 8:15









        Fred

        38.2k1238




        38.2k1238




















            up vote
            3
            down vote













            For this kind of problem it is worth knowing about the factor theorem



            This says if $a$ is a root of your polynomial $f(x)$ i.e. $f(a)=0$ then $x-a$ is a factor of, i.e. divides, the polynomial.



            In these kinds of problems it is worth trying a few values such as $pm1, pm2$.



            In your example $f(1)=0$ so $x-1$ divides your polynomial, allowing you to factorize it as $(x-1)(Ax^2+Bx+C)$ where you need to find $A,B,C$.






            share|cite|improve this answer






















            • Useful, I can't adequately express my gratefulness!
              – AmirhoseinRiazi
              Aug 22 at 9:21










            • Thank-you. I am very pleased it helped you.
              – PM.
              Aug 22 at 9:25














            up vote
            3
            down vote













            For this kind of problem it is worth knowing about the factor theorem



            This says if $a$ is a root of your polynomial $f(x)$ i.e. $f(a)=0$ then $x-a$ is a factor of, i.e. divides, the polynomial.



            In these kinds of problems it is worth trying a few values such as $pm1, pm2$.



            In your example $f(1)=0$ so $x-1$ divides your polynomial, allowing you to factorize it as $(x-1)(Ax^2+Bx+C)$ where you need to find $A,B,C$.






            share|cite|improve this answer






















            • Useful, I can't adequately express my gratefulness!
              – AmirhoseinRiazi
              Aug 22 at 9:21










            • Thank-you. I am very pleased it helped you.
              – PM.
              Aug 22 at 9:25












            up vote
            3
            down vote










            up vote
            3
            down vote









            For this kind of problem it is worth knowing about the factor theorem



            This says if $a$ is a root of your polynomial $f(x)$ i.e. $f(a)=0$ then $x-a$ is a factor of, i.e. divides, the polynomial.



            In these kinds of problems it is worth trying a few values such as $pm1, pm2$.



            In your example $f(1)=0$ so $x-1$ divides your polynomial, allowing you to factorize it as $(x-1)(Ax^2+Bx+C)$ where you need to find $A,B,C$.






            share|cite|improve this answer














            For this kind of problem it is worth knowing about the factor theorem



            This says if $a$ is a root of your polynomial $f(x)$ i.e. $f(a)=0$ then $x-a$ is a factor of, i.e. divides, the polynomial.



            In these kinds of problems it is worth trying a few values such as $pm1, pm2$.



            In your example $f(1)=0$ so $x-1$ divides your polynomial, allowing you to factorize it as $(x-1)(Ax^2+Bx+C)$ where you need to find $A,B,C$.







            share|cite|improve this answer














            share|cite|improve this answer



            share|cite|improve this answer








            edited Aug 22 at 9:25

























            answered Aug 22 at 8:33









            PM.

            3,1982822




            3,1982822











            • Useful, I can't adequately express my gratefulness!
              – AmirhoseinRiazi
              Aug 22 at 9:21










            • Thank-you. I am very pleased it helped you.
              – PM.
              Aug 22 at 9:25
















            • Useful, I can't adequately express my gratefulness!
              – AmirhoseinRiazi
              Aug 22 at 9:21










            • Thank-you. I am very pleased it helped you.
              – PM.
              Aug 22 at 9:25















            Useful, I can't adequately express my gratefulness!
            – AmirhoseinRiazi
            Aug 22 at 9:21




            Useful, I can't adequately express my gratefulness!
            – AmirhoseinRiazi
            Aug 22 at 9:21












            Thank-you. I am very pleased it helped you.
            – PM.
            Aug 22 at 9:25




            Thank-you. I am very pleased it helped you.
            – PM.
            Aug 22 at 9:25

















             

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