Explicație pas cu pas:
b) A = {2, 3, 6, 9}
B = {1, 2, 3, 6, 9, 18, 27, 54}
=> A ⊂ B
c) 2⁰ = 1, 2¹ = 2, 2² = 4, 2³ = 8
A = {1, 2, 4, 8}
B = {1, 2, 4, 8}
=> A ⊂ B
d) |x + 3| < 5 <=> -5 < x + 3 < 5
-5 - 3 < x < 5 - 3
-8 < x < 2
A = {-7, -6, -5, -4, -3, -2, -1, 0, 1}
|x| ≤ 7 <=> -7 ≤ x ≤ 7
B = {-7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7}
=> A ⊂ B
