Question

Va rog ajutati-ma . Se da problema :
1. Elementele multimii
A={x€N | 4 < 3x– 2 ≤ 10} este:
a) {2,3,4}
b) {3,4}
c) {7,8,...,12}
d) {5,6,...,10}
Va rog eu frumos pls repede dau coroana!

Answer 1

$A=\left\{x\:\in\:\mathbb{N}\:|\:4 < 3x - 2 \leqslant 10\right\}$

$4 < 3x - 2 \leqslant 10 \: | + 2$

$6 < 3x \leqslant 12 \: | \div 3$

$2 < x \leqslant 4 = (2,4]$

$x \: \in \: \mathbb{N} = > x \: \in \: \left\{3,4\right\}$

$= > b)\left\{3,4\right\}$