Răspuns:
Explicație pas cu pas:
x∈N, x≤8, ⇒ A={0,1,2,3,4,5,6,7,8}
x e multiplu (natural) de 3 și x≤24, ⇒B={0,3,6,9,12,15,18,21,24}
0<x<27, deci x-1<26 și x-1 este multiplu de 4, ⇒C={1,5,9,13,17,21,25}.
a) A∪B={0,1,2,3,4,5,6,7,8}∪{0,3,6,9,12,15,18,21,24}={0,1,2,3,4,5,6,7,8, 9,12,15,18,21,24}
b) B∪C={0,3,6,9,12,15,18,21,24}∪{1,5,9,13,17,21,25}={0,1,3,5,6,9,12,13,15,17, 18,21,24,25}
c) A∪C={0,1,2,3,4,5,6,7,8,9,13,17,21,25}.
d) A∪B∪C={0,1,2,3,4,5,6,7,8,9,12,15,17,18,21,24,25}
e) A∩B={0,3,6}.
f) A∩C={1,5}
g) B∩C={9,21}
h) A∩B∩C=∅
i) A
