Răspunsuri

2014-10-06T20:36:52+03:00
18/2n +1
n = 1 , 3 , 9

18/2x1 = 18/2 = 9+1=10
18/2x3 = 18/6 = 3+1=4
18/2x9 = 18/18 = 1+1=2
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2014-10-06T20:37:23+03:00
 \frac{18}{2n+1}∈N
2n+1|18
2n+1∈{1,2,3,6,9,18}
2n∈{0,1,2,5,8,17}
n∈{0, \frac{1}{2} ,1, \frac{5}{2} ,4, \frac{17}{2} } (1)
n∈N (2)
Din (1) si (2) ⇒ n∈{0,1,4}




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