1) x - 5

x = 5

D (f) = (-беск; 5) v (5; +беск)

2)

x = +-

D (f) = (-беск;- ) v (-; ) v (; +беск)

3) 12x + 6 >= 0

12x = -6

x = -0,5

D (f) = [-0,5; +беск)

4) D(f) = (-беск; +беск)