Translate the following into interval notation: "The union of all numbers greater than eight, and less than or equal to negative four".

() is for

[] is for ≤≥

greater than 8 means

x>8 or

8 to infinity not counting 8 or

(8,∞)

less than or equal to - 4 is

x≤-4 or

from - ∞ to - 4

or

(-∞,-4]

the infinity has a () sign since you cannot equal infinity, you can approach it

U is unity so

(-∞,-4] U (8,∞)