Answer:
5/36
Explanation:
To carry out this subtraction of fractions we need to obtain and use the LCD (lowest common denominator). This LCD is the smallest new denominator evenly divisible by both 12 and 9. In this case the LCD is found by multiplying 12 and 9 together, obtaining 108.
Then 11/12 = 99/108 and 7/9 = 84/108, and
11/2 - 7/9 becomes the equivalent 99/108 - 84/108, or 15/108.
This fraction should be reduced as much as possible. Note that both 36 and 108 are evenly divisible by 12, so 15/108 = 5/36. This is the answer you want.