Question

A = { n ∈ N | 6 ≤ 2n + 4 < 40 }
n ∈ ....

Answer 1

6 ≤ 2n + 4 <40 |-4

2 ≤ 2n < 36 |:2

1 ≤ n < 18

A={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17}