Question

Fie multimile ; A ={ x∈ N / 2x + 2∈ Dindice 12 } si B={x ∈ N /5≤3x -1 ≤ 11}. Determinati multimile : A , B , A reunit cu B , A - B , A intersectat cu B si B - A. Va roggggggggg! Am nevoie urgenta.

Answer 1

2x+2∈ {1,2,3,4,6,12}⇒ 2x∈ {-1,0,1,2,4,10}⇒ x∈{0,1,2,5} ⇒ A= {0,1,2,5}

5 ≤ 3x-1 ≤ 11   /+1
6 ≤ 3x ≤12  /:3
2  ≤ x ≤ 4⇒ x∈{2,3,4}⇒ B={2,3,4}

AUB={0,1,2,3,4,5}
AnB={ 2 }
A\B= {0,1,5}
B\A={3,4}