6/7(-9) I don't know the fraction then I have to subtract 9 from the answer and get a fraction help
I am not sure what you want either :/
Maybe this :/
$$\\\frac{6}{7}-9 \\\\ =\frac{6}{7}-1-8 \\\\=-\frac{1}{7}-8\\\\=-8-\frac{1}{7}\\\\ =-8\frac{1}{7}$$
It is hard to understand what you are trying to find. Can you state the problem in another way?