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The third proportional of the following numbers (x - y)2, (x2 - y2) = ?

A. (x + y3) (x + y4)

B. (x + y)4 (x - y)2

C. (x - y) (x + y)2

D. (x + y)2 (x - y)3

Answer: Option C

Solution(By Examveda Team)

$$\eqalign{ & {\text{Let,}} \cr & a = {\left( {x - y} \right)^2}, \cr & b = \left( {{x^2} - {y^2}} \right){\text{and}} \cr & c\,\,{\text{be}}\,{\text{the}}\,{\text{third}}\,{\text{proportional}} \cr & {\text{Therefore}}\,\,\,a:b::b:c \cr & i.e.\,\,\,c = \frac{{{b^2}}}{a} \cr & \Rightarrow c = \frac{{{{\left( {{x^2} - {y^2}} \right)}^2}}}{{\left( {x - y} \right)}} \cr & \,\,\,\,\,\,\,\,\,\,\, = \frac{{{{\left( {x - y} \right)}^2}{{\left( {x + y} \right)}^2}}}{{\left( {x - y} \right)}} \cr & \,\,\,\,\,\,\,\,\,\,\, = \left( {x - y} \right){\left( {x + y} \right)^2} \cr} $$

This Question Belongs to Arithmetic Ability >> Algebra

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Comments ( 2 )

  1. Subrat Das
    Subrat Das :
    4 months ago

    This formula is not for third proportion .

  2. Hizbu Rahman
    Hizbu Rahman :
    2 years ago

    I think this question is wrong because the solution is not for this question please verify question with answer and make possible corrections
    Thanks in advance

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