Question

Fie multimile :
-A={x|x=14a+3,a∈N}
-B={y|y=21b+11,b∈N}
Calculati A intersectat cu B
Rezolvari complete cer!

Answer 1

X=14a+3,a∈N,daca a=0⇒14·0+3=3  daca a=1⇒14·1+3=17  daca a=2⇒14·2+3=31   daca a=3⇒14·3+3=45  daca a=4⇒14·4+3=59  avem A={3,17,31,45,59,73,87,101,115,...}                                                                         y=21b+11,b∈N , daca b=0⇒21·0+11=11 , daca b=1⇒21·1+11=32 ,  daca b=2⇒21·2+11=53 ,daca b=3⇒21·3+11=74 ,daca b=4⇒21·4+11=92  avem B={11,32,53,74,92,103,124,145,166,...}   si acum facem Aintersectat cu B={3,17,31,45,59,73,87,101,115...}intersectat {11,32,53,74,92,103,124,145,166,,,}=Ф⇒Aintersectat cu B=Ф⇒AsiB sunt multimi disjuncte deoarece nu au nici un element comun.