To add these fractions, we first need to find a common denominator. The least common multiple of 9 and 17 is 153.

(-7/9 + 3/17) + (-2/9)
= (-7*17/153 + 3*9/153) + (-2*17/153)
= (-119/153 + 27/153) + (-34/153)
= (-92/153) + (-34/153)
= -126/153
= -14/17

Therefore, the sum of the fractions is -14/17.