Question

aflati elementele multimilor:A={x/apartine lui N,x=3n+1,n <6}
B={y/y apartine lui N ,y=5n+3,n <5}
Calculati:A reunit cu B,A intersectat cu B,A-B,B-A

Answer 1

A={ x ∈ N , x=3n+1,n<6}
A={3*0+1,3*1+1,3*2+1,3*3+1,3*4+1,3*5+1}
A={1,4,7,10,13,16}

B={y I y ∈ N, y=5n+3,n<5}
B={5*0+3,5*1+3,5*2+3,5*3+3,5*4+3}
B={3,8,13,18,23}

A∪B={1,4,7,10,13,16} ∪{3,8,13,18,23}={1,3,4,7,8,10,13,16,18,23}
A∩B={1,4,7,10,13,16}∩{3,8,13,18,23}={13}
A-B={1,4,7,10,13,16}-{3,8,13,18,23}={1,4,7,10,16}
B-A={3,8,13,18,23}-{1,4,7,10,13,16}={3,8,18,23}