Question

true or false:

Answer 1

false.

Answer 2

\[what\ is\ the\ question\]

Answer 3

\[9\notin\left\{ 3,9,18 \right\}\]

Answer 4

well; since 9 IS an element of the set .... id say its false to assume otherwise

Answer 5

or do we account for poor notation?

Answer 6

\[Its \ false\ because\ it\ belongs\ to\ the\ set\]

Answer 7

Your statement says: 9 does NOT belong in the group (3,9,18) but as you can see, it clearly does, so the statement that it does NOT is false.