Write each inequality using interval notation,

9. 4≤x<6
(i got [4,6) )

11. x≥4

12. x≤5

9 is correct. The ) means not including.

The rest.. Here, read.

http://www.mathsisfun.com/sets/intervals.html

Good luck!

This post was edited by Rws on Aug 26 2013 07:18pm

where is 10?

11: [4,inf) or [4,inf]

12: (-inf,5] or [-inf,5]

before the 'or' the normal/standard way, after the 'or' the notation if you are using the closed real line

This post was edited by brmv on Aug 27 2013 12:22am

You never use closed brackets on an interval going towards infinity

perhaps start studying mathematics and you'll find out when you do it

I would use the parenthesis (not square bracket) when you need to use infinity in this case.

assuming that the op was more likely high school math i put those as normal/standard way
but it really would depend on the class, so i put the other as potential alternative