To subtract fractions, we need to have a common denominator.

First, let's convert all the mixed numbers to improper fractions.

9 15/14 = (14 9 + 15)/14 = 141/14
2 5/1 = (1 2 + 5)/1 = 7/1 = 7
4 10/7 = (7 * 4 + 10)/7 = 38/7

Now, rewrite the equation with the improper fractions:

141/14 - 7 - 38/7

Now, find a common denominator, which is 14:

(141 - 98 - 38)/14
(43 - 98)/14
-55/14

So, the final answer is -55/14