Do you switch the Direction of the < sign when you multiply,divide or both or neither by a negative number

like in something like this -3x < 9 is it 3x > -3 ? and could you give me one more easy example of some other situations

Whenever you multiply/divide a side of an inequality by a negative number flip the sign.

Ex.
-x < 6
x > -6
You could also do this same problem like this (to show you why you flip the inequality):
-x < 6
add x to both sides
0 < 6 + x
subtract 6 from both sides
-6 < x
or
x > -6

Ex.
5 - 3x < 10
-3x < 10 - 5
x > -5/3