How do I find the E U F and the E U F

Question

E= {w│w ≤ 4}

F= {w│w < 6}

Write E U F and E ∩ F using interval notation. If the set is empty, write Ø

Answer 1

E U F will be the combination of E and F.

E U F = (-∞,6)

E ∩ F will be only what E and F have in common. This excludes (4,6), which leaves

E ∩ F = (-∞, 4]