Question

Ajutor !

pag.43 ex.21 a)​

Answer 1

Răspuns:

Explicație pas cu pas:

Pentru multimea A, inmultim toate partile cu 2, obtinem:

-2<3x+7≤22 |-7, ⇒-9<3x≤15 |:3, ⇒-3<x≤5, deci A={-2,-1,0,1,2,3,4,5}

Pentru multimea B, inmultim inegalitatea cu 8, obtinem:

-16≤5x+9<24 |-9, ⇒-25≤5x<15 |:5,  ⇒-5≤x<3, Deci B={-5,-4,-3,-2,-1,0,1,2}

A∪B={-2,-1,0,1,2,3,4,5}∪{-5,-4,-3,-2,-1,0,1,2}={-5,-4,-3,-2,-1,0,1,2,3,4,5}

A∩B={-2,-1,0,1,2],   A\B={3,4,5},  B\A={-5,-4,-3}