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B= ( x/x apartine N si x +1 apartine D18 )

te roggg ajuta ma sa rez asta!!


Răspuns :

B={x|x∈N,x+1∈D₁₈}
x+1∈D₁₈
x+1∈{-1,-2,-3,-6,-9,-18,1,2,3,6,9,18}
x∈{-2,-3,-4,-7,-10,-19,0,1,2,5,8,17}
x∈N=>S:x∈{0,1,2,5,8,17}
B={0,1,2,5,8,17}