Question

elementele a =(xen|2x+3<9)

Answer 1

$A=\left \{ x\:\in\:\mathbb{N} \:|\:2x+3<9\right \}$

$2x + 3 < 9$

$2x < 9 - 3$

$2x < 6 \: | \div 2$

$x < 3$

$x \: \in \: \mathbb{N} = > x \: \in \: \left \{ 0,1,2 \right \}$

$= > A=\left \{ 0,1,2 \right \}$