Question

A={x|x€N*, 2x +5 < 13

Answer 1

x €N* =>X >0


x=1
2x+5=2+5=7 =>7 <13

x=2
2x+5=2×2+5=4+5=9 => 9 <13

x=3
2x+5=2×3+5=6+5=11 => 11 <13

x=4
2x+5=2×4+5=8+5=13 => 13=13 acesta nu este bun deci avem :


A={1,2,3}