Answer:
-27 and -33.
Explanation:
If the number have 9:11 of ratio, this can be expressed like this: 
 . Because a ratio represents a equivalence between two fractions.
. Because a ratio represents a equivalence between two fractions.
The problem says that their difference is 6, which can be expressed like: 

Where x and y are the unknown numbers.
So: 
 ; we replace this equation in the ratios one.
; we replace this equation in the ratios one.

To calculate the second number we use: 

Hence, the two numbers that fit with the 9:11 ratio and their difference of 6 are -33 and -27.