**best answer gets brainliest! ** using a number line, find both the intersection and the union of the following intervals:
a) (−3, +∞) and (4, +∞)
b) (−∞, 2) and [0, +∞)
c) (−∞, 6) and (−∞, 9)
d) [1, 5] and (0, 8]