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1/x + 1/y = 1/2016 please help find x and y

x and y have to be natural numbers

 Nov 12, 2016
edited by Guest  Nov 12, 2016
edited by Guest  Nov 12, 2016
edited by Guest  Nov 12, 2016
edited by Guest  Nov 12, 2016
 #1
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0

1/x + 1/y = 1/2016. Well, one obvious solution is:

x =4032 and y =4032!!!!!!,because

1/4032 + 1/4032 = 1/2016

 Nov 12, 2016
 #2
avatar+129840 
0

1/x + 1/y  = 1/2016

 

I'm  assuming that x and y must be different natural numbers

 

We have a "formula" that says that

 

1/n =  1/[ n + 1]  +  1/ [n (n + 1)]

 

So...if n = 2016.....then   1/[ n + 1]  +  1/ [n (n + 1)]    =

 

1/2017 + 1 /[ (2016)(2017)]  =     get a common denominator

 

[2016 + 1 ] /  [ 2016 * 2017] = 

 

2017 / [ 2016 * 2017]  =

 

1/2016

 

So......x =  2017   and y = 2016*2017  = 4,066,272

 

 

 

cool cool cool

 Nov 12, 2016
 #3
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+5

Well, almost any multiple of 2016 of x will give you a solution for y such as :
x=6,048 and y=3,024
x=8,064 and y=2,688
x=10,080 and y =2520
............etc.

 Nov 12, 2016
 #4
avatar+129840 
0

Guest is correct....I should have stated that my solution isn't unique.....!!!!

 

He is using the identity that, for k =1, 2, 3, 4, 5........

 

1/n  =

 

1/[k*n] +  1/ [k * n / (k -1)]   =

 

1 [/k*n] + [k-1] / [ k *n ]  =

 

[ k - 1 + 1 ] / [k*n ] =

 

k /[ k*n  ] =

 

1/n 

 

 

 

 

 

 

 

cool cool cool

 Nov 12, 2016

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