Answer:
4 and 8
Step-by-step explanation:
(a)
f(0) for x = 0 , that is the interval x < 5, thus
f(0) = x + 4 = 0 + 4 = 4
(b)
f(6) for x = 6 , that is the interval 5 ≤ x < 7, thus
f(6) = 8