Question

scrie prin enumerare elementele multimii {n € N | 6<sau egal 2n +4<20}

Answer 1

$M=\left \{ n\:\in\:\mathbb{N} \:|\:6\leq 2n+4<20\right \}$

$6 \leq2n + 4 < 20 \: | - 4$

$2 \leq2n < 16 \: | \div 2$

$1 \leq n < 8 = [1,8)$

$n \: \in \: \mathbb{N} = > n \: \in \: \left\{1,2,3,4,5,6,7\right\}$

$= > M=\left\{1,2,3,4,5,6,7\right\}$