Hello
To solve this question, we were given a particular function and asked to evalute when the function is defined with a particular variable

For f(-6)

For g(-9)

For f(-9) + g(-9)

for g(-6) - f(-9)

For f(-9).g(-7)

For f(-6) / g(-7)

From the calculations above, i believe you must've seen your mistaken and taken the necessary correction.
Therefore the answers are
1 = 27
2 = 297
3 = 336
4 = 87
5 = 6825
6 = 27/175