Question

rapid dau 14 pucte


A={x e N*/ x+2 mai mic sau egal cu 6}

B={ j e N/j=3la x , x e A }
AUB A/B B/A

Answer 1

x+2≤6 => x≤4 => x∈{1,2,3,4}
j=$3^{x}$ , x∈A =>
=> j=$3^{1}$ => j=3
=> j=$3^{2}$ => j=9
=> j=$3^{3}$ => j=27
=> j=$3^{4}$ => j=81
A={1,2,3,4}
B={3,9,27,81}
AUB={1,2,3,4,9,27,81}
A/B={1,2,4}
B/A={9,27,81}
AПB={3}