What it the inequality for this interval? (-00, 2] u (8,00)

Interval notation tells you what values where the function is defined. It’s defined all the way from negative infinity to positive 2, then there’s a gap all the way to positive 8, then we continue on to positive infinity. So x, would be literally every single number besides the number between 2 and 8. Oh and don’t forget that brackets mean included, so 2 is also a value that’s acceptable.

x is less than or equal to 2
and
x is greater than 8