Stabiliti valoarea de adevar a propozitiilor:

a) 11 apartine {8,9,10,11,12,13} b) {2,4,7,11,16,22} inclus {2,4,5,7}


c) 12 nu apartine { n | n apartine N, n =2a, a apartine N}

d) {1,7,13} inclusa {0,1,2,...,23,24}. va rog ajutatima.