Two questions regarding exponents












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Question #1:



$$frac{frac{x^{2}y^{-3}}{3z^{{2}}} - frac{z^{-3}y^{-3}}{3x^{2}}}{frac{x^{-4}y^{2}}{3z^{-2}}}$$



Question #2:



$$(x^{-1} + y^{-1})^{-1}$$



Answer to Question #1:
$$frac{x^{6}z - x^{2}}{y^{5}z^{5}}$$



Answer to Question #2:
$$frac{xy}{x + y}$$



These questions are from the book Just in Time Algebra & Trig for Calculus, Section 1.4.



I am not able to reach the final answer for both of these problems, and I could use some help. And if you can clarify which "laws of exponents" are being used as well, because the second question above seems easy but I can't get the answer.



Thanks.










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  • $begingroup$
    to answer your question as to which exponent rules to use, use these: $x^a = frac{1}{x^{-a}}$ ; $x^{-a} = frac{1}{x^a}$ ; $x^a cdot x^b = x^{a+b}$ ; $(x^a)^b = x^{a cdot b}$ ;
    $endgroup$
    – Hossien Sahebjame
    Dec 23 '18 at 17:55


















0












$begingroup$


Question #1:



$$frac{frac{x^{2}y^{-3}}{3z^{{2}}} - frac{z^{-3}y^{-3}}{3x^{2}}}{frac{x^{-4}y^{2}}{3z^{-2}}}$$



Question #2:



$$(x^{-1} + y^{-1})^{-1}$$



Answer to Question #1:
$$frac{x^{6}z - x^{2}}{y^{5}z^{5}}$$



Answer to Question #2:
$$frac{xy}{x + y}$$



These questions are from the book Just in Time Algebra & Trig for Calculus, Section 1.4.



I am not able to reach the final answer for both of these problems, and I could use some help. And if you can clarify which "laws of exponents" are being used as well, because the second question above seems easy but I can't get the answer.



Thanks.










share|cite|improve this question









$endgroup$












  • $begingroup$
    to answer your question as to which exponent rules to use, use these: $x^a = frac{1}{x^{-a}}$ ; $x^{-a} = frac{1}{x^a}$ ; $x^a cdot x^b = x^{a+b}$ ; $(x^a)^b = x^{a cdot b}$ ;
    $endgroup$
    – Hossien Sahebjame
    Dec 23 '18 at 17:55
















0












0








0





$begingroup$


Question #1:



$$frac{frac{x^{2}y^{-3}}{3z^{{2}}} - frac{z^{-3}y^{-3}}{3x^{2}}}{frac{x^{-4}y^{2}}{3z^{-2}}}$$



Question #2:



$$(x^{-1} + y^{-1})^{-1}$$



Answer to Question #1:
$$frac{x^{6}z - x^{2}}{y^{5}z^{5}}$$



Answer to Question #2:
$$frac{xy}{x + y}$$



These questions are from the book Just in Time Algebra & Trig for Calculus, Section 1.4.



I am not able to reach the final answer for both of these problems, and I could use some help. And if you can clarify which "laws of exponents" are being used as well, because the second question above seems easy but I can't get the answer.



Thanks.










share|cite|improve this question









$endgroup$




Question #1:



$$frac{frac{x^{2}y^{-3}}{3z^{{2}}} - frac{z^{-3}y^{-3}}{3x^{2}}}{frac{x^{-4}y^{2}}{3z^{-2}}}$$



Question #2:



$$(x^{-1} + y^{-1})^{-1}$$



Answer to Question #1:
$$frac{x^{6}z - x^{2}}{y^{5}z^{5}}$$



Answer to Question #2:
$$frac{xy}{x + y}$$



These questions are from the book Just in Time Algebra & Trig for Calculus, Section 1.4.



I am not able to reach the final answer for both of these problems, and I could use some help. And if you can clarify which "laws of exponents" are being used as well, because the second question above seems easy but I can't get the answer.



Thanks.







algebra-precalculus






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asked Dec 23 '18 at 17:36









nooranoora

1




1












  • $begingroup$
    to answer your question as to which exponent rules to use, use these: $x^a = frac{1}{x^{-a}}$ ; $x^{-a} = frac{1}{x^a}$ ; $x^a cdot x^b = x^{a+b}$ ; $(x^a)^b = x^{a cdot b}$ ;
    $endgroup$
    – Hossien Sahebjame
    Dec 23 '18 at 17:55




















  • $begingroup$
    to answer your question as to which exponent rules to use, use these: $x^a = frac{1}{x^{-a}}$ ; $x^{-a} = frac{1}{x^a}$ ; $x^a cdot x^b = x^{a+b}$ ; $(x^a)^b = x^{a cdot b}$ ;
    $endgroup$
    – Hossien Sahebjame
    Dec 23 '18 at 17:55


















$begingroup$
to answer your question as to which exponent rules to use, use these: $x^a = frac{1}{x^{-a}}$ ; $x^{-a} = frac{1}{x^a}$ ; $x^a cdot x^b = x^{a+b}$ ; $(x^a)^b = x^{a cdot b}$ ;
$endgroup$
– Hossien Sahebjame
Dec 23 '18 at 17:55






$begingroup$
to answer your question as to which exponent rules to use, use these: $x^a = frac{1}{x^{-a}}$ ; $x^{-a} = frac{1}{x^a}$ ; $x^a cdot x^b = x^{a+b}$ ; $(x^a)^b = x^{a cdot b}$ ;
$endgroup$
– Hossien Sahebjame
Dec 23 '18 at 17:55












1 Answer
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$begingroup$

Hint to your first Question:
Write
$$frac{x^2}{3z^2y^2}-frac{1}{3x^2y^3z^3}=frac{x^4z}{3x^2y^3z^3}-frac{1}{3x^2y^3z^3}$$
and you will get
$$frac{(x^4z^2-1)}{3x^2y^3z^3}cdot frac{3x^4}{y^2z^2}$$
The result should be $$frac{x^2 left(x^4 z-1right)}{y^5 z^5}$$






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    $begingroup$

    Hint to your first Question:
    Write
    $$frac{x^2}{3z^2y^2}-frac{1}{3x^2y^3z^3}=frac{x^4z}{3x^2y^3z^3}-frac{1}{3x^2y^3z^3}$$
    and you will get
    $$frac{(x^4z^2-1)}{3x^2y^3z^3}cdot frac{3x^4}{y^2z^2}$$
    The result should be $$frac{x^2 left(x^4 z-1right)}{y^5 z^5}$$






    share|cite|improve this answer











    $endgroup$


















      1












      $begingroup$

      Hint to your first Question:
      Write
      $$frac{x^2}{3z^2y^2}-frac{1}{3x^2y^3z^3}=frac{x^4z}{3x^2y^3z^3}-frac{1}{3x^2y^3z^3}$$
      and you will get
      $$frac{(x^4z^2-1)}{3x^2y^3z^3}cdot frac{3x^4}{y^2z^2}$$
      The result should be $$frac{x^2 left(x^4 z-1right)}{y^5 z^5}$$






      share|cite|improve this answer











      $endgroup$
















        1












        1








        1





        $begingroup$

        Hint to your first Question:
        Write
        $$frac{x^2}{3z^2y^2}-frac{1}{3x^2y^3z^3}=frac{x^4z}{3x^2y^3z^3}-frac{1}{3x^2y^3z^3}$$
        and you will get
        $$frac{(x^4z^2-1)}{3x^2y^3z^3}cdot frac{3x^4}{y^2z^2}$$
        The result should be $$frac{x^2 left(x^4 z-1right)}{y^5 z^5}$$






        share|cite|improve this answer











        $endgroup$



        Hint to your first Question:
        Write
        $$frac{x^2}{3z^2y^2}-frac{1}{3x^2y^3z^3}=frac{x^4z}{3x^2y^3z^3}-frac{1}{3x^2y^3z^3}$$
        and you will get
        $$frac{(x^4z^2-1)}{3x^2y^3z^3}cdot frac{3x^4}{y^2z^2}$$
        The result should be $$frac{x^2 left(x^4 z-1right)}{y^5 z^5}$$







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Dec 23 '18 at 17:51

























        answered Dec 23 '18 at 17:41









        Dr. Sonnhard GraubnerDr. Sonnhard Graubner

        77.4k42866




        77.4k42866






























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