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Ask iit jee aieee pet cbse icse state board community Community Discussion Question: plz solve this
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sourab_MCA (19)

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if x2-y2=101 then


x2+y2=?


 


thnx


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securitas2311 (23)

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5101

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shinee (247)

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can u plz post the soln

SHREYA
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sourab_MCA (19)

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solution plz

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rahul1993 (354)

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squaring both the sides


x4 + y4 -2x2y2 = 10201


x4 + y= 10201 + 2x2y2


adding 2x2y2 to both sides


(x2 + y2)2 = 1012 + (2xy)2


now it is of the form a2 + b2 = c2        pythagorus triplet


now if you look at the table for pythagorean triplets                     


  (www.math.utah.edu/~alfeld/teaching/ptt.html)   (look in the 8th line second last  value)


51012=1012+51002


x2 + y2 = 5101


PLS CORRECT IF WRONG

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kaymant (1269)

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x2-y2=101 => (x+y)(x-y) = 101.


Since, 101 is a prime, the factorization is 101=101 * 1.


So (x+y)(x-y) = 101 * 1


Hence, x+y = 101 and x-y = 1 (since x+y and x-y are integers)


Solving we get x =51, y =50. Hence x2+y2=5101.

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rudra.panda (2557)

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Very very easy...................



x^2-y^2=101


\Rightarrow (x-y)(x+y)=101\\\\\Rightarrow  (x-y)(x+y)=101\times 1\\\\\Rightarrow (x+y)=101\ and\ (x-y)=1(As\ (x+y) > (x-y))


So x+y=101


      x-y =1


So x=51 and y=50


 x^2+y^2=51^2+50^2\\\\=5101


God does not care about our mathematical difficulties. He integrates empirically. ~~~Albert Einstein (1879-1955)~~~~
To divide a cube into two other cubes, a fourth power or in general any power whatever into two powers of the same denomination above the second is impossible, and I have assuredly found an admirable proof of this, but the margin is too narrow to contain it.~~~Pierre de Fermat (1601-1665)~~~

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