(8p) Scrieţi sub formă de interval mulţimile:
a) A = {x ∈ R\−2 ≤ x < 7}=
b) B = {x ∈ R\x < 9}=
c) C = {x ∈ R\|x| ≤ 7}=
d) D = {x ∈ R\x ≥ −1}=