help me.....im stupid.....

redical x^2 - y^2 = 6

the answer is x=10 & y=8 .......................but how can i get it..............thnx

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- Jan 20th 2009, 06:23 AMlebanonalgebra problem
help me.....im stupid.....

redical x^2 - y^2 = 6

the answer is x=10 & y=8 .......................but how can i get it..............thnx - Jan 20th 2009, 08:27 AMrunning-gag
Hi

I suppose that x and y are integers

$\displaystyle \sqrt{x^2-y^2} = 6$

$\displaystyle x^2-y^2 = 36$

$\displaystyle (x-y)(x+y) = 36 = 2^2 \cdot 3^2$

(x-y) being smaller than (x+y) the possibilities for ((x-y),(x+y)) are (1,36) ; (2,18) ; (3,12) ; (4;9) ; (6;6)

Their sum must be even because (x-y)+(x+y)=2x

Remain 2 possibilities

(2,18) => x=10 and y=8

(6,6) => x=6 and y=0